I think it's a great site. Check the feedback on the person you're going to transact with and there should be no trouble. I've done a few transactions without any trouble
I have bought and sold FAL kits and rifles here with ZERO issues, but like most sites I do recommend using the feedback rating to help decide as well as communicating with buyer/seller before completing transaction......
I've sold a gun and my father has bought guns, and nether one of us has had any problems. If I remember right, there is a certain point where money is sent before the gun is, so check out the feedback of the seller.
I've probably made ~15 or so transactions on gunbroker. All but two have been good experiences. One guy just flat out misrepresented an item and then refused to honor his terms of inspection/return. Never got any help from GB after 6 months back and forth and eventually sold the rifle for a loss. The other case was just a guy who probably wasn't familiar with firearms and so sent me a broken gun. He was very apologetic and offered to take it back but I fixed it myself.
All in all, it is a good site. Just read the user feedback and check the description/photos clearly. As a general rule I stay away from 'AS IS' because that is just asking for trouble. If you have any doubt about a firearm, ask the seller about it first.
I've bought and sold dozens of guns and gun related items on GB over the years with only 1 issue (an item I tried to purchase was not as described and returned for a full refund - no harm). I'm particular about bidders and sellers having time on there and pay attention to feedback, payment and shipping terms.
I have purchased two rifles, a lower, mags and ammunition on there with zero problems. If you check feedback and work with the sellers/buyers and communicate the transactions go very smoothly.
Have made many purchases thru them and have never had an issue whatsoever. Like using ebay, looking at the sellers feedback and rating is the most important thing. I'll continue to use them too without hesitation.
Used their services many times and only had one problem, a deadbeat bidder.
Although gunbroker reps did refund my listing fees it took several months and many messages to get it done.
I still use them as a go-to for most firearm related things.
I have used them many times without issue. My recommendation is to do your due diligence and make sure the seller is reputable. I purchase NIB Colts and the amount of fake boxes, manuals, etc out there is incredible.