Big fan! I've been a member for 5 months now and get a haircut roughly once a month... still worth the membership.
The strongest reason that I like their membership model is that going out for a haircut no longer feels like a commitment (in terms of both cost and style). I'd rather pay the haircut price for the month and have the option of 2 haircuts as needed, rather than paying each time for an uncertain haircut! (Literally describing the benefits of a Subscription business model).
Every stylist is reliably skilled and I don't have to worry about getting a bad cut. Reservations are in 20 minute time slots and is readily available each day! The only downside is that you can make reservation for that day (and not for future dates) which is fine... it would result in more no-shows anyway.