I like the online check-in, it's very helpful. The estimated wait times do not seem accurate, but i understand that it is hard to get those accurate. It would also be helpful to know if there is a grace period for arrival at the store without losing spot in line.
I could recommend a specific SC stylist but not the chain. The "Check-in" procedure does not insure you of your slot. A "walk-in" could take it while you're on the way to the shop.