Working with a 5 Guys vendor, I've been to about 150 of their locations (roughly 15% of their stores) in the last 18 months. I must say, my biggest surprise has always been how consistent they are. Sure, they're not all 100% perfect but with 2 or 3 exceptions they've all been pretty close. Granted, my entire experience has been east of the Mississippi so i guess it could be different the further from their Va HQ you get.

I do know for a fact that every 5 guys has at least 2 mystery shopper visits per week and they're extremely anal about cleanliness.

And yes, I have gained about 10 pounds since i started visiting them