I use my own "people" hair dryer on the boys. The warm setting is too hot to use so I mostly use cool, which is still warmer than the air...but I will switch it to warm for a few seconds and then back to cool for a few minutes...and then back and forth....that way the dryer is warmer than room temp but its not too hot.
I have used both a commercial hand dryer and a cage dryer as well. The cage dryer dries the dog, however, it's like air drying, but speedier because the dryer is pushing out warm air...so the dog is still unbrushed and their hair doesn't look nice as if you hand dry and brush it. It's great for dogs with short coat who don't need a lot of brushing to look nice. It's also nice to put a dog in a cage dryer for a few minutes to air dry before hand drying them.
The commercial dryers are much more powerful than our regular hair dryers. They literally will blow the water right off a dog. Because we have little guys, I probably would put the dryer on a low setting which would be about the same strength as a regular blow dryer. IMO, a regular blow dryer works as well as a commercial one does....on these little guys. If we were talking about a different breed, such as a newfie or a collie or a golden retriever, I would definitely say save yourself time and energy and get a commercial dryer...but with these guys, a little hand held works just as good, if not better.
Hope this helps a little