We booked through this website, although ILMAGP had no idea who they were. There was another intermediary, and between them (FHR.com and ILMAGP) they had no idea we were booked? I think the fault was with ILMAGP because during an earlier phone call they seemed to know who we were, but by the 2nd call they had no clue!! We had to resubmit card details (but thankfully we were not charged again). Positives: staff were prompt to answer phones, and people we met were very friendly and polite. Would give them benefit of the doubt and use them again, but if admin went wrong again would probably look elsewhere.
The whole process went very smoothly from start to finish. The drop off point was easy to find, the driver was waiting for me when I arrived (even though I was earlier than the time I had booked for)and the form-filling was the most straightforward I've come across for this type of parking. Collecting the car after landing was an equally simple experience. Both of the parking staff I dealt with were unfailingly welcoming and polite. This is certainly the best Meet & Greet service that I've used at Gatwick and I'll definitely use them again.