I have played with both phones. And both have things I like and dislike about them. I just cant seem to choose between the two. Everytime I think i've made up my mind something comes along to make me change it. I mainly use my phone for talking and texting. The Mp3 player doesnt matter to me. krzr earpiece is louder but Z710i reception seems a bit better. the krzr is sleek and can fit right in my pocket but is also a fingerprint magnet and i would have to constanly wipe it clean. The z710i seems more durable and well built while the krzr seems delicate. The Z710i camera is better but it doesnt have zoom like the Krzr. I really cant decide. which one would you go with and why? i will be using it with T-mobile if that makes a difference.