I have bought many, many things from them - both for home and work - going back into the 1990's and have always been completely happy. Hadn't used them for years, but recently I was shopping for a bluetooth GPS and all the usual online merchants were charging list price. Just for the heck of it, I looked at Mac Mall and was surprised to see they had it in stock and it was 10% cheaper than anywhere else.
Placed the order and had it in my hands a few days later. So I have nothing but good things to say about them.... but I'm just one person, so caveat emptor. 🙂