Honestly I haven't used 4g at all. I can test it and see and get back to ya, but I personally don't use 4g that much if at all.
4g is faster yes, but it's still not in as many areas as is 3g, plus from what I have read and researched, 4g does put a strain on the battery life, and I'm all about the battery life.
I am going to be buying a 3500, or 3800 as soon as I get the cash.
The phone doesn't get that much fatter with a bigger battery, it's only slightly bigger, basically that hump at the bottom?, that's the difference you'll see, it just takes that out, so it makes the back more even, as apposed to having that slope or hump at the very bottom of the phone. Coming from the warp1 and it's HUGE fat size with a 3500, that's a MAJOR improvement. The phone won't be as slim but it won't be drastically fat either, plus I will have the battery life I want.
Back to the 4g, as I said it eats battery more than 3g does, plus as I heard it, at least right now, boost throttles 4g back to 3g speeds after a certain amount, and mostly because 4g is I guess I'd say spotty, it's not as saturated in areas as 3g is, even as long as it's been out.
I guess in the simplest terms, I just make it simple and stick to 3g, as 3g is fine speed wise for me personally. If I need fast(er) speeds I just use WiFi, and even that seems to be around even more so than 4g is.
I'll do some testing when I go to work, as where I live is in a more rural area, so my bars and speed are less than desired, even at 3g speeds.
I'd say here my avg has been around 1mbps, at times I may reach 1.2 but rarely, mostly it's between 0.70mbps - 1bps. Sad I know
......that's why I use my dsl WiFi most of the time.
I'll give both 3g and 4g a try when I get to work and get back to ya.