I'm digging this so far, Sunset Riders seems to suffer the most from screen tearing as others have shared.
I do notice that overall the video quality seems a little blurry or muted. Just not as clean as an original arcade board. It's seems a little dark too, will need to pay with the Monitor settings.
Plus the left hand side of the image is often cut off for CPS1/2/3 games. Overall though, I think it's awesome. Been using PB3 as a way to try games to see if I like it enough to acquire the real hardware. Convenience is certainly it's biggest strength, and performance is decent enough.
Ideally it'd have an extra 30% CPU power and be more customisable. It's a black box, borderline hack-job and not easy to alter. DogP looked into it, seems to run FBA, but the menu system and input handling is all compiled into a frankenbinary. Would be nice to get some Mame titles in there, but for that one would need to understand how inputs are handled, roll a custom version of Mame for it along with an alternative to their menu system... in short, not worth the effort.
For the price, it's awesome though, I mean seriously, a JPAC costs about the same as this, but it's a full solution and still has a great collection of games, if you're happy with the games it has and accept that you can't add to the game selection.