T-Mobile doesn't have it easy these days. Not only is it the only major U.S. carrier to not carry the iPhone, it's about to become the only carrier without a high-speed LTE network. But with some rebranding and some new phones the carrier is hoping to resurrect itself in the eyes of you, the cellphone-loving customer.

Today, T-Mobile and HTC are announcing that their latest high-end Android phone, the HTC One S, will be available on the network starting on April 25. The phone will cost $199.99 with a two-year contract, and offers quite a lot.

It has a beautiful 4.3-inch qHD Super AMOLED display, which makes images and webpages look great. It has a fast 1.5GHz dual-core Qualcomm Snapdragon S4 processor, and a high quality 8-megapixel camera. It runs the latest version of Google's Android Ice Cream Sandwich operating system, with HTC's Sense 4 software, which adds some enhancements.

On top of that all, the phone is only 7.8mm thick - by comparison, the iPhone is 9.3mm thick.

All those specs add up to a very well-rounded phone, which is comfortable to hold and easy to use. But that key ingredient, LTE - which is making its way into competing phones from Verizon, AT&T, and now even Sprint - seems to hold it back.

But T-Mobile isn't dismayed, and said its the new ad campaign, featuring an edgier "No More Mr. Nice Girl," is meant to take on this very challenge.

"The 'Alter Ego' campaign illustrates our market challenge and opportunity. With this campaign, we're telling the market, loud and clear, that T-Mobile is a competitor - that we will win and retain customers by delivering affordable, innovative 4G services," T-Mobile Senior Vice President of Brand and Advertising Peter DeLuca told ABC News.

DeLuca said the One S will be featured loud and clear in the campaign: "The new image showcases our challenger approach and being more assertive about who we are and what we stand for, like network speed and delivering cutting-edge devices like the HTC One S."

It's an assertive move and the One S is a a very nice and well-rounded smartphone. But AT&T announced just today that its HTC One X, which is very similar to the S but has a larger display, will be available on May 6 for $199.99 with LTE.

So T-Mobile's likely to have a hard time no matter how hard it tries.