Some are calling it the best Android phone yet.  The HTC’s One M8 — which replaces last year’s well-received One — not only improves on the previous One’s stylish aluminium casing with more metal and color options, but also adds a host of other hardware upgrades.

Among those upgrades are a faster 2.3GHz (2.5GHz in Asia), quad-core Qualcomm Snapdragon 801 processor, 2GB of RAM, a slightly bigger screen (5-inches at 1920 x 1080 resolution or 441 ppi) protected with Corning Gorilla Glass 3, self-amplified “BoomSound” front stereo speakers which are supposedly 20% louder, and an improved front-facing “selfie” camera that’s now 5-megapixels and records 1080p video, just like the rear cam.

On its backside the phone now has two camera lenses: one is the same “UltraPixel” 4MP lens on the original HTC One, and the second lens is there only to add depth.  The depth lens enables you to change the focus after you take a shot, or add different effects for different layers of an image, using the updated camera software.  On the downside, although the Qualcomm processor is capable of 4K video recording and playback, the One’s camera lenses are not.

While the new One only comes in 16GB or 32GB, it adds a MicroSD slot for adding up to 128GB of additional storage.  The phone has an improved (but still non-removable) battery of 2,600mAh, with a claimed talk-time of up to 20 hours.  It also can charge to 80 per cent within an hour, thanks to Qualcomm’s FastCharge technology.

For connectivity, the One M8 offers Bluetooth 4.0, NFC, 4G LTE, DLNA, HTC Connect, and IR remote control for TV usage.  One notable difference on the cellular side is that unlike the first HTC One, the M8 now requires a nano SIM card, like with Apple’s iPhone 5S.

On the software end, the One M8 adds several new features, mostly new photo editing tricks in the camera application. The One M8 comes with Android 4.4 and HTC’s new Sense 6.0 Android skin.  This includes the latest version of HTC’s BlinkFeed news reader, which you can disable from appearing on the launch screen if you wish.  Probably the most useful new software feature is Motion Launch, which similar to last year’s LG G2, keeps the phone “always-on” in a passive power mode.  Double tapping the screen lets you wake the device or put it back to sleep.

The One M8 now comes in three color options: gunmetal grey, silver and gold — but if you’d rather forgo the phone’s sexy exterior with the extra protection of a case, HTC has a couple of cases for you.  One is a normal flip case, and the other is HTC’s new “Dot View” case that lets you see the weather and time through the dots on the case.

The new One is available now from major carriers in the US, Canada, UK, and worldwide.  If you don’t want to be tied to a contract, you can also buy it unlocked directly from HTC or get the Google Play Edition with stock Android.  Last year’s One (M7) will remain on sale at a cheaper price.

Most reviewers love the new One M8 overall — with the 4MP camera being their primary complaint.  To see if the camera is a trade-off you’re willing to make or not, check out the highlights we’ve rounded up below of some of the most detailed HTC One M8 reviews.

Android Central

“The new HTC One…handles outdoor shots better. Low light is still sort of hit-and-miss. And the 4-megapixel resolution (in addition to being a hangup for the specs-at-all-cost crowd) quickly shows its limitations if you zoom into a picture at all. …Fortunately, things have greatly improved in the M8’s camera app, including being able to launch it without waking the phone first by holding it in the landscape orientation and hitting the volume button.”

Ars Technica

“In most cases, the M8 can’t stand up to the market-leading iPhone 5s, which regularly produces pictures with richer colors. M8 images always seem like washed-out, dreary versions of whatever we were shooting. …Thanks to the big speakers and bezel, the One M8 is the largest 5-inch Android phone, which is not a good thing. If you can get over the bloated size and poor camera, the M8 is a fine phone, and there’s even a Google Play Edition available that will have better software and faster updates.”

BGR

“HTC’s Duo Camera introduces several great new features and the M8’s camera software is better than ever, but the quality of photos captured by the UltraPixel camera remains a weak spot on HTC’s flagship phone. Washed out colors remain my largest gripe, though the clarity of photos captured by the One also lags top rival devices, and photos often have an abundance of noise.  Even still, the new HTC One is the best all around Android smartphone the world has ever seen.”

CNET

“4.5/5: It runs on a powerful quad-core processor and Android KitKat, the stereo speakers deliver excellent sound, and the depth-sensing camera brings a ton of useful features. The bad: The Bad The One M8’s battery is not removable, making it harder to replace once the battery inevitably wears out. The phone’s sealed chassis is not water-resistant, and the One M8’s photos look less sharp than competitors.”

Engadget

“88/100: While the One’s all-metal exterior looks great and is quite durable, it’s still susceptible to small scratches. Even if your phone has only fallen victim to wear and tear, it likely won’t look as brand-new as the day you bought it.  …The Duo Camera’s new abilities are fun and useful, the performance is fantastic, battery life has improved significantly, the new version of HTC Sense is even better, and the company continues to improve features like BoomSound and BlinkFeed. …The new One [is] still at the top of our list, but its slick finish makes it uncomfortable to hold. What’s more, we’d like to see some more improvements to the One’s display and UltraPixel technology, which were once among the best in their class.”

Pocket-Lint

“5/5: Bigger isn’t always better, but the HTC One is balanced. It’s a touch smaller than the Sony Xperia Z2, the big difference being that the top and bottom space are “empty” on the Sony handset, whereas the One offers the excellent front-facing BoomSound speakers. …We were happy with the performance of the 2013 HTC One, but the 2014 model casts a shadow over it. There’s more pop, more speed, and it makes the older device feel noticeably slower. …Overall, the HTC One (M8) is a wonderful reinvention of the 2013 handset.”

Stuff.TV

“5/5: The sixth Sense (HTC’s pun, not ours) does make Blinkfeed even more awesome. Blinkfeed collects social media posts and news from your favourite sources, together with calendar appointments, and gathers them in a beautifully presented pane of your Home screen. You’re not just limited to the 1400-odd official HTC content partners, but can add any RSS feed you like. More impressively, the HTC now monitors your activity, works out what most interests you and presents that first.”

The Register

“The processor doesn’t just improve the battery life. At 2.3GHz and quad-core too, it zips along brilliantly. …Something HTC likes to shout about is how the phone sounds. Called Boomsound, it really is very good – loud and clear. …HTC has clearly worked very hard on the One: the problem it has is that it’s starting in the same place as all its rivals. With the latest chips from Qualcomm and latest versions of Android from Google, it’s very hard to differentiate.”

The Verge

“8.5/10: I only really understood how well-made the new One is when I held it in my hands. …I love the One’s camera interface, [and] I love what it lets me do with my photos. I just don’t like most of the photos I take. The UltraPixel sensor sees remarkably well in the dark, able to capture a usable picture in virtually any situation, but my praise for the One’s pictures rarely goes beyond “usable” in any situation. Photos are mushy and soft, as if nothing’s ever quite in focus. Even the 5-megapixel front-facing camera, the ultimate selfie machine, is better in a lot of situations. …I desperately wish it took better pictures, and I’m reluctant to buy or recommend it until it does.”

Trusted Reviews

“9/10: A fantastic phone. The only issue you may want to consider is the camera. It’s outstanding in low-light and very fast, but it has a strange approach to exposure metering and purple chroma noise issues that purists will notice. Does this make it bad camera? Categorically not, especially as the Duo camera (imperfect as it is) adds a unique and fun feature that’s perfect for Facebook, Instagram, Twitter and co. But it is something worth considering.”