I personally despise the Burris.The general consensus is that even the best quality MRDS on the market, the Trijicon RMR, still isn't 100% up to the task, and occasionally some of them fail under the increased load of having to cycle on a slide. Some people have issues with them, some don't, so I'd say the technology is still not 100% there, though it has progressed substantially in the past several years.
Less expensive RDS tend to not be as durable in this configuration, and also tend to be more likely to have problems maintaining a zero. The Burris FastFire seems to be hit or miss. I've shot a bunch of guns with the FF, including a couple mounted on shotguns, a few on AR's and PCC's, and a few on handguns. One handgun was a P229 Sport in .357Sig with the factory comp. That one wasn't a high round count gun, which is probably some of the reason it seemed to work alright.
FWIW: I have a Burris FFII Reflex on a Beretta 92FS. The good news is that it has been reliable; I've even mounted it on my M627 .357 Magnum with excellent results on the revolver. On the Beretta; however, I've always had bore sight issues with the FFII. In fact I shoot the Beretta * better with open sights. (* True for my 92FS, 92G Vertec, and even my Taurus PT92.)Reflex