I just took a trip from one end of Mississippi to the other, including a day in Memphis, and I can say without any doubt that C Spire does NOT specifically hate the AL/FL coast. Their network is as bad in their home state as it is here. Lots of 1x areas, slow to dead 3G, even in the smallest of towns. Network coverage was surprisingly weak even along the I-55 corridor and I found a few places just off the highways where it was weak enough to cause my phone to bug out* and go crazy.
About the only city where it really seemed to work well was Hattiesburg, specifically around the mall on the outskirts of town. Even though every part of MS and Memphis I checked was EV-DO Rev A, this was the only town where the data was at all speedy. Certainly a lot faster than what we get in Alabama!
Overall though, it was so "not better" in the rest of Mississippi I felt compelled to come on here and complain. I really thought it was just the coast they hated, but that's apparently not true. Their network is crap pretty much everywhere. I'm so, so disappointed. Now that T-Mobile has HSPA+ in Mobile and Pensacola and Verizon has true 4G LTE in Mobile, Baldwin + Escambia Counties, C Spire's network is really starting to lag behind.
Beyond the carrier, I'm also getting tired of having to pull the battery in my phone 3x a week because Google Maps or some other supposedly competent program locks it up. I sure has worn the lustre off my love for Android.
Sorry for my rant, guys, but I had to get that off my chest. I feel better now. Thanks!
* - The Samsung Galaxy S series apparently has a bug where a weak 3G signal on the 800 MHz band causes RF interference in the chip that detects key presses on the soft keys, causing lots of false registers to occur. In my case, any time it was transferring data and I set the phone on my lap or leg while in the car, it would spontaneously start registering the back key as being held down, causing all kids of weird issues like not being able to load apps and rendering the power button useless because it was taking screenshots. As soon as I left rural Mississippi (but near I-55) or got on wifi, the problem went away. It only happens once in a blue moon in Baldwin County but happened dozens of times while I was in MS. Weird. I would have thought their MS network was much more robust.