I changed to tiger MT-2216 KV900 motors after one of my stock motors had a bad bearing fairly early on. Motors are better balanced, smoother, slightly more efficient, better build and bearings but also about double the price. The ones I got come with a standard 5mm round prop shaft which lets me use lots of different props much easier then with the non standard DJI motors.
It goes pretty well with some 9050 triblade props, dont expect a miracle when it comes to new motors but these are clearly better then the stock DJI. You cant change the spec too much due to the Phantom shell and ESC's but the Tiger motors are some great little motors I think.
[youtube]http://www.youtube.com/watch?v=7jTnb-szvYE[/youtube]