Good on you for switching, though I don't think I would feel comfortable sending my child to a ped that would be great only for "normal" kids.
We found ourselves in the exact same boat. DD, who just turned 19mos, is globally delayed due to congenital hypothyroidism that went undiagnosed until she was almost 1. Because of our original ped who, like yours, wouldn't listen to me...."Oh, you think she's getting too big? Feed her less." Seriously.
In two months of our new ped, he referred us to an early intervention program within our school district, and my daughter is now seeing the full range of specialists so that we can try to catch her up. It makes me sick that he picked up on all of this immediately, and my last ped was so blase about everything.
Best of luck to you on your new journey, and good on you for being a mama bear! I played the "Dr. Knows Best" game for far too long, being a first time mama, and also not wanting to acknowledge that my daughter's normal just might be quite different from everybody else's.
: single mom extraordinaire, keeper of eew since 02/09