I have one that I used for a few batches when I got back into homebrewing from a couple of years break.
Number 1 the packet beer it makes is quite bad, but still drinkable. It's low quality but it is good after a hard day in the yard mowing the lawns etc. but I wouldn't use it as the main source of beer.
The machine is pretty well built, the pressure relief valve mentioned is set to 15 PSI. It's basically a rubber grommet that expands when it reaches that pressure to vent. I'd assume over time that this would have issues and become worthless but a solid lid and a hole drilled with a airlock would be a good replacement.
It has these defoamer disks that are probably useless. They are to keep the krausen down. They probably work but it's a hassle and I guess you can only use them once.
The one problem I had with it was the inconsistant pressurisation during carbonation. Once the beer is brewed then you put it in the fridge. CO2 is absorbed and so the pressure goes to 0PSI. You then jet in some more using the soda bulbs to bring it up to ~12PSI. Over a few hours that's absorbed into the beer taking pressure back to 0PSI. Then you need to "jet" in the gas again to get a decent pressure to serve. But now it's carbonated and under pressure so you get a lot of foam and head on the beer.
And then the pressure drops to 0PSI and you're fighting it again for your next pour. I'm not sure if this is how it's supposed to be designed or operate. I guess I'm over pressurising when I dispense (it probably doesn't need to be 12PSI since there's no tubing etc.). But when it's at 0PSI it just trickles out so you need to pressurise it a bit to pour a nice beer. It seems that when you do one jet into the machine with the CO2 (with the machine full of beer) it gets to about 5PSI immediately, so there's very little control with how much CO2 you pressurise the machine with.
TL;DR: It's not a badly constructed machine, the beer provided in the packets is pretty terrible though. If you do AG or extract you could ferment in it (or probably better to ferment elsewhere and rack into Beer Machine and bottle the rest) or just use it as a dispenser. It's an excellent fermenter, certainly a better fermenter than it is a dispenser (I've found). You could probably ferment and then bottle from it to get precise carbonation since it's carbonation method is pretty error prone and occasionally disastrous, but that may be my skill with using the pressure valve. Overall probably worth less than $50 for the vessel and a box of CO2.
