There are lots of posts on this board regarding Club Mobay - check out the search feature. You don't specify arrival or departure (or both). I've used the arrival service once and felt like it was a waste of money because there was no line at all. I've also arrived in Mobay without arrival service and stood in line for 2 hours, so it's a toss-up depending on what day and time you arrive.

We've used the service several times on departure. It was nice to relax and make use of their bar. The snacks are okay, but nothing special. We always wait until we are actually at the airport and thru the airport check-in to decide if we have enough time to make it worthwhile.