I've used them once - and based on their inspection I didn't buy the car in question
They're quite good if you tell them in detail what it is you're looking for - which problems you want them to check out, which areas you want them to photograph. And they're quick too - which is great if you want them to check out an ebay car, for instance.
I've looked in state for a while and haven't quite found what I want. I agree w/ the rust comment. The car I'm looking at is in California so it shouldn't be a rust problem (that's what I want the inspection for). I talked to the owner several times. It sounds like it's doesn't have a rust problem. The inspection service will let me know. The car is a '73 and the owner's had it since '75 (he bought it from a friend). Hopefully it will work out.