At a press event in New York City this week, T-Mobile USA announced the launch of its faster “4G” LTE mobile broadband service, the elimination of all contract plans in favor of no-contract, “unlimited” data plans, and unsubsidized phones including the iPhone 5, Galaxy S 4, HTC One, and BlackBerry Z10.

At the event, T-Mobile CEO John Legere didn’t mince words about his competitors AT&T, Verizon, and Sprint. “Stop the bullshit,” he said, referring to the carriers’ traditional contract subsidy model. “Carriers are really nice to you… once every 23 months. This is the biggest crock of shit I’ve ever heard in my entire life. Do you have any idea how much you’re paying? …If you come to T-Mobile, you’ve signed your last contract.”

Legere is so confident that you’ll like T-Mobile’s new LTE network, he is challenging customers to either love it or leave it. “If we suck this month, drop us. Go somewhere else,” he said.

T-Mobile’s LTE service is now available in San Jose, Las Vegas, Phoenix, Houston, Kansas City, Washington, D.C., and Baltimore.  New York City is expected to have LTE service by early summer, and the carrier promises LTE coverage for 100 million Americans by the middle of 2013, growing to coverage for 200 million by the end of the year.

In areas not yet with T-Mobile LTE coverage, T-Mobile’s new high-speed data plans will use its HSPA+ 3G network, which can average download speeds of 20Mbps.  Although T-Mobile calls its data plans “unlimited,” like other carriers it will throttle your data down to (potentially) 2G speeds (as low as 300 Kbps) if you exceed a certain limit.  For $50 per month that limit is 500MB of high-speed data, and for $60 per month, you get 2.5GB of high-speed data.  For $70 per month, T-Mobile promises no limits — this price drops to $120 per month for two people on a plan, and $150 per month for a family of four.

Along with the new plans, T-Mobile is now selling all of its phones at unsubsidized prices.  The 16GB iPhone 5, HTC One and Samsung Galaxy S4, for example, are expected to sell on T-Mobile for $579 when they are available — April 12 for the iPhone 5, May 1 for the Galaxy S4, and “soon” for the HTC One, which is currently held back due to supplier delays.

For these phones you can choose to pay the entire cost up front and have the device unlocked, or choose T-Mobile’s payment plan of $100 ($99.99) down plus 24 monthly payments of $20 each.  T-Mobile says it will also make the Galaxy Note 2 available once it completes an LTE software update for the device, and a new Sonic 2.0 Mobile Hotspot will round out the list of LTE-capable devices.

If you aren’t interested in waiting for the iPhone, S 4, Galaxy Note 2, or HTC One, T-Mobile has a few other well-reviewed phones to choose from right now.  For example, the BlackBerry Z10 can be yours for $532, or $100 down plus $18 per month for two years, while the Android Samsung Galaxy S II or the Windows Phone 8 based Nokia Lumia 810 each sell for $360, or zero down and $15 per month.

If you choose to pay off your phone right away or early in the payment plan, T-Mobile says it will unlock your phone, so if you decide to switch carriers, you can take your phone to another carrier that supports it.  Because all plans are now off contract, there are no early termination fees.  And if you return your phone to T-Mobile before your financing agreement plan ends, T-Mobile says it will credit your agreement with the current market value of the device.

T-Mobile’s new plans give it a slight edge in cost savings over Sprint, Verizon, and AT&T.  For example, T-Mobile’s iPhone 5 on its $70 plan would cost you $2,260 over two years, while on Verizon, the iPhone 5 with unlimited talk and text plus 2GB of data will cost $2,600 over two years, and on AT&T and Sprint, the two-year cost (with unlimited data on Sprint and 4GB on AT&T) will set you back $2,840.  It’s not an apples to apples comparison since  each carrier offers different plans, but you get the gist.  The Verge compares the two-year cost of an iPhone 5 for individuals, couples and families on all four major US carriers here.

As InfoWorld and TechCrunch point out, the new data plans are a relative bargain compared to AT&T and Sprint, but overall, there is not a huge difference in total costs to coax some people to switch carriers.

What do you think of T-Mobile’s new offerings? Are you planning to switch, or are you happy with your current carrier?