Build quality- you bought a MyTouch 4G. That's why lol. HTC's flagship phones have amazing build. (Sensation for 2011, Desire HD for 2010) Music - If its skipping, there's something wrong with your kernel. Don't use the one the comes with CM7...it sucks. I'll find a better one for you later. Stability- As long as you wipe fully and all, you shouldn't have problems with this. Idk. Battery - This is also related to the kernel. I usually get 20-30 hours on a single charge with moderate usage. Try recalibrating and setting the network to "2G Only" overnight. Different kernels help a lot too.