I'm currently with T-mobile, and I can talk on the phone while surfing at the same time. When I run a speed test while talking I get about the same data rate up / down as I do when I'm not on the phone (about 2-3Mbs). I tried this recently at an AT&T store on the One X, because I've heard rumors that AT&T is throttling users while they are on calls. It was amazing to see - off call (using the LTE radio) data rates were amazing - 20 Mbs up and down. In call, rates were absolutely horrible - about .5 Mbs down, and virtually 0 up. This confirmed what I have been hearing / seeing posted on the web, and makes me not want to go with AT&T due to this. Which is why I am asking about Verizon. For those of you with LTE phones, what are your data rates (according to speedtest) when you are on a call? I'd be happy if they were the same as what I get now with T-mobile. Can anyone post their results? Thanks!