To be honest with you...after having the 12" installed I could have done a 10" with no doubts about it later. But as with my bigger is better mentality I opted for the 12"
My settings on the head unit is set to 3-4 bass for the wife and I prefer 5-6 but thats it. at those settings I know I'm not taxing the sub or amp in the least. Kinda nice to pump it up on the songs that I like allot of bass but 98% of the time I keep it at a level of 5. So yea, a 10" would have worked out great. The sound matting was my best decision out of the whole process. Good luck in whatever you decide.