groomer for border collie, any tips

Jaew hair is so thick and he hates the dryer. Last groomer just shave everything and he look like a sheep for 1 month lol. Now i look for someone who do double coat properly. I ask 3 question on the phone first: do they use high velocity dryer or the normal one, can I stay in the room, and how long the session is. If they say dont worry it is fine, i skip them. I also think the price is not everything. The cheap place take 40 minute and very rough, the expensive one take 2 hour. Balance is important krub.