T-mobile doesn't have 4G in Atlanta. All they have is HSPA, Sprint does have 4g,tmobile only in 7 markets.
And yes their data is slow on 3g,but they don't get dropped calls like tmobile.
And how do you figure Verizon is third? Based on what?
Great drops, most reliable network, works everywhere when tmobile and att can't say the same
Hspa+ is considered 4G in the US. What are you talking about? Then even if you don't consider it 4G, what difference does it make when it's faster than Sprints 4G WiMAX and in par with its LTE?
I speak on Verizon from experience. I just had service with them on my iPhone 5 up until a month ago. I've had all the carriers within the past 2 years except Sprint because of how poor the 3G is and how limited their LTE coverage currently is. The stuff I'm saying is coming from personal experience with the networks not blogs or heresay.
The GSM networks worked better for me than the CDMA ones when I go there. Not saying Verizon was good too. Their service was reliable but I got better speeds with AT&T and Tmobile.