Don't get me wrong, currently I am a Tmobile customer, however with an ad campaign stating that it is "time to set the record straight" It seems unethical to blatantly provide false advertising.
Tmobile has an HSPA+ network. This is far from a 4G network. At most it is a 3G+ or 3.5G network. Technical specifications aside, HSPA+ is merely just an upgrade of the existing HSPDA 3G data network, unlike LTE or WiMax which are entirely new networks that need to be deployed. While none of these technologies reach the speeds that the ITU originally used to define the term 4G, an upgrade to an existing network can hardly be considered a completely new generation of technology. It would be like tuning the engine of an older car and claiming that it is a new car.
Lets move onto the comparisons on their website:
For the Tmobile vs Sprint comparison, they compare a HSPA+ Samsung Galaxy S II with a 3G capable iPhone 4GS. Right off the bat due to the hardware specifications of these two devices the comparison is weighted in Tmobiles favor. It also is misleading to iPhone fanboys who may think that they can get similar results by bringing an unlocked iPhone over to Tmobile. The fact is that the GSM version of the iPhone sold by AT&T uses different frequencies for 3G than what Tmobile uses, so in reality if you put an iPhone onto Tmobile at best you will only be getting EDGE 2G speeds.
The AT&T comparison again pits a Samsung Galaxy II capable of HSPA+ speeds against an iPhone 4GS that can only obtain 3G HSPDA speeds. Again based solely on hardware Tmobile has an unfair advantage. As well as misleading people into believing that the network is what is faster. AT&T has the same "4G" network as Tmobile in most areas, a HSPA+ network, and has been lighting up their LTE network in most major markets recently. LTE could be considered an actual 4G network, unlike HSPA+ and it also offers greater speeds.
Finally the Tmobile vs Verizon comparison once again pits the iPhone 4GS against the Samsung Galaxy II. Same situation as the other two carriers that they compare above. This is misleading advertising. It is like comparing the speeds of a Porsche with a Chevy Volt on a public highway, while the owner of the Volt has a Ferrari and a race track to prove that they are faster.
Not sure why Tmobile would want to "set the record straight" with an apples to oranges comparison.
I am a Tmobile customer, not because of the blatantly fraudulent advertising, but because the pricing structure of their prepaid plans provides me the greatest benefit at the current time. Until Verizon or AT&T show reasonable rate plans for prepaid LTE service, or Sprint opens up their LTE network that they are going to replace their WiMax network and offer it on Boost or Virgin, then Tmobile remains a fairly decent value for the speeds provided on their prepaid plans. However, pay careful attention to the fine print, the $50 plan only provides around 100MB of "4G" data - when you go over the allowed data on your plan you are throttled down to 2G EDGE speeds, not 3G. Why? well that is fairly easy to answer - because HSPA+ IS 3G, so the only lower tier would be 2G.