I have attended a number of their in-person and online-only auctions, as well as have purchased a few things and looked at / investigated multiple items in every auction catalog over the last 6+ months.
They do have a fair amount of legitimate offerings, but anyone considering bidding on anything from them should be warned:
Any jewelry items / gemstones etc that come with a so-called "appraisal" will turn out to be junk. They use a company called GLA to do their appraisals, which come in at hundreds of times more than the actual value. I purchased an item that was GLA "appraised" to be worth over $20,000, for $500 in one of their auctions. I took it to a local jeweler they said it was basically worthless except for the scrap/melt value of about $50. Which isn't to say you shouldn't buy any of these items from them, but do not pay more than 1% to 3% of the so-called appraisal value, and do not expect to re-sell it nor get a good buy.
Some of the jewelry / gemstones etc will be appraised incorrectly to begin with. The item I purchased was stated to be one type of stone, and it turned out to be a different type entirely.
All sales are final, no refunds, and it is your responsibility to verify the facts beforehand. That is their policy, so even if they misrepresent something in their catalog, you have no recourse.
Don't bid on anything in their online-only auctions unless you are 100% sure you know what you're getting. I purchased an item that had "condition issues", and when it arrived, it was basically something that someone should have thrown in the garbage. It was worthless and unusable. They do provide photos, but did not include photos of the "condition issues". They do not offer in-person previews of their online-only items, and will not answer questions during the auction.
The vials of gold flakes they sell for $30 to $50+ each are actually worth less than a dollar each. Check eBay. Not sure why people are buying these - the photos are misleading and make them seem much larger than they are.
The "retro" advertising signs they sell are 90% reproductions. Every so often they have real vintage signs, but the vast majority are reproductions that are distressed to look old.
The auctioneer will bait and mislead [lie to] bidders. They frequently say things like "These sell for $100 on eBay" when in fact they do not, or the item itself is not allowed on eBay to begin with (n**i, KKK etc type of items).
They simulcast their auctions on proxibid.com, liveauctioneers.com, icollector.com and auctionzip.com, so if you use any of those sites be sure you know who is holding the auction.
If you do plan to bid on anything from them, I would strongly urge you to do so on in person, and with your own full knowledge as to what the item is and what it is worth. Don't get caught up, and don't be swayed by what anyone else says (they have employees and friends in the audience that will "talk up" items as though they were just another bidder).