OP is talking about RI Maingate, not Garden Grove (which I believe is a bit further away from the Maingate). I haven't stayed at the TPS but it seems a bit far away from the parks if that's where you indeed to spend most of your time; if you have a car and are fine for parking each day then I don't see why you can't try it out but the RI Maingate is close enough to walk, and the breakfast/facilities are great too.