I use them for beach club access, but it has the same issue as gym access - you have to get in early in the morning as the allocations are limited. That aside, it seems to work quite well.
The deals they do on shops and restaurants are utterly useless to me, far too expensive for what I can manage with a family.
It may be coincidence, but for the first few months in DXB I had no spam at all, but within a couple of weeks of joining APC, I started getting daily text and email spam and phone calls from Jakarta and Tunisia based "investment firms" (the Jakarta company said they got my details, including family and employment details, from APC).