I am also considering this service and am finding it very difficult to deal with them. Lots of red flags: horrible website, unclear descriptions of the service, opaque pricing, etc. I also found a couple of reviews that say this service is basically a scam; all they do is walk you around the airport and take you to lines that you had access to anyway.

I've emailed them three times with a simple question (what kind of priority security do they provide -- is it just the Premier Access lane or something faster?) and they can't answer my question. They just send canned replies with bullet point lists of benefits or replies that answer a completely different question.

I am ready to give up and try a different service like Royal Airport Concierge, which seems to be larger and has a MUCH better website.