I have used them several times buying some common sony stuff- through greentoe. Got some pretty good deals.
Never had a problem. Once shipping was about a week delayed, but I wasn't in a hurry.
I would use them again. I personally use B&H or Roberts for most of my purchases- they both have an aisle named after me- but I saved several hundred dollars going through greentoe. Worth it for me if I am not in a hurry.