I'm way into the GB's lately. I'm in three of the big ones and I'm enjoying the hell out of them.
I like that the prices are very low, the three and a half (one is not actually a group buy, that dude is a vendor by every definition, but whatever) have a lot of members, I like the testing setup, and I like the ease of ordering. Also, it means the ship-to-me happens from a US address, so if there's a customs seizure, my name is not on the package.
Also, if there IS a customs seizure or a zero pep result (both of which have happened on Gb's I was in), then there's someone ELSE handling the back and forth yes-you-did-no-I-didn't bullshit that would exhaust me in no time.
I also kind of like the twists and turns. I'm waiting on a replacement from a buy that came back underfilled from back in the fall. They worked with the vendor and argued with the vendor and eventually went to a totally different vendor to replace, and we got the kits....which came back zero pep, so now there's ANOTHER replacement coming. (I'm not bothered; I'd never use something before a test came back, and I'm still using the underfilled batch, which ends up being free because of the replacement. So as long as the replacement ultimately does happen, I come out ahead.)
@ZippityDooDah has been pretty vocal about the downsides of Gb's, and I don't actually disagree with him. I may change my tune after the second or third time a GB runs off with my money. But I think they're right for what I want and what I'm willing to accept at this very moment. I have everything I NEED, and I mostly just order a kit of something or other that my mom wants (if I got scammed on a my-mom order, she would never know it happened; I'd replace out of my own pocket) or something I just want to have, and the long turnaround keeps me buying SLOWLY, which is good because an addict is an addict and clearly this is feeding some deeper impulse.
(Please don't DM me for GB links, it's hard for me to find them and I really save "on request" helping work for employment situations.)