I have been an InSpa customer for about six years. Most of the services I've received (waxing and pedicures) have been just fine.
In the last year or so however, I have noticed a markable "stingyness" in the willingness to do anything "extra." For example, on a basic bikini wax, you get just that, even if there are a few stray hairs, if you know what I mean.
The only truly bad experience I had was at the Mill Creek location in which I arrived for a massage and was told they couldn't do it because I was finishing up antibiotics. Noone EVER asked me about this when I made my appointment. I had a wax appointment that was supposed to follow my massage, and when I said I didn't want to wait around for the appointment, the massage therapist announced, in the lobby full of people, to the receptionist that I wouldn't be keeping my appointment because I was on antibiotics. Not cool. I will say that I complained to the manager and was compensated fairly for the inconvenience and embarrasment.
If you are on a budget, this place is a great deal because you aren't allowed to tip and their fees are a bit lower than other spas.
My advice is cliche - you get what you pay for. If you don't want to pay for frills, don't expect them.