I don't really think it will make much of a difference in where you go in terms of logging hours but you will have more actual time in flight at CHD. The two biggest flight schools in the valley are both located at DVT and that leads to longer delays waiting to take off or land. Also the practice areas around CHD are closer and a little bit less congested. You'll be fine at either one, though. Good luck, you'll be at ATP mins before you know it!