Same here. It's convenient to where I stay, uses small fast boats (which I prefer), goes out fairly early but not extremely so (ditto), chooses sites by a vote of those aboard (ditto), tries to keep divers with similar experience levels together (ditto), and gives me a good experience every time I go out with them. As you say, it works for me so why change?Although the shop I dive with is on "the list", I can't say it is the best. It works great for me and it provides everything I need.
If I was going to COZ 5-6 times a year I might try other places, but for my annual trip I am quite happy with the DM's, Captains, boats, schedules, and all the employees at the shop so why change.