I've never personally dealt with these guys, but you will find a stack written about them in various forms on the net. Some claim them to be a rip off and some seem to like them!
I do know that they are a decent sized operation, and when you have turnover like they do you're always going to have some unhappy customers who didn't quite know what they were they actually buying because of their inexperience in the liquidation market.
Suggest you take a look at some sites like rip of report and so on. Like I said, you'll find some negatives, but you have to balance that against their volume as far as I'm concerned.
The key factor.........your on knowledge of how the industry works. Doesn't matter how good the supplier is, if your expectation don't match what they are selling, then you will feel screwed....even though they are just selling what they usually sell...........
Anyone thinking of dealing in the liquidation market needs to educate themselves before moving forward, because while there are some fantastic deals available, there are some seriously BIG pitfalls that inexperienced buyers fall into.