Damn, wasn't aware Apple made Intel systems that were too slow to get 60fps. Here I was hoping the Mac would be my one reprieve from the "my old dinosaur can't run it, ergo your emulator sucks" posts.
I can assure you, the best minds in the emulation world have looked at and helped optimize my code. For what all it does, it is quite efficient.
And if you think ZSNES or Snes9X is perfect, you can take a look here:
https://zsnes.bountysource.com/development/bug_report
That list is far from inclusive, and excludes dozens of game specific hacks. Snes9X has even more hacks.
bsnes has zero hacks, and zero known bugs. Not even Nestopia on the NES can command that level of compatibility. I can't even think of another emulator for any system that can make such a claim.
If your computer is too slow, or you don't see any problems with your games, stick with those emulators. Please don't judge the quality of an emulator because it won't run on your specific hardware. Many people have newer hardware that can run it just fine; my 2-year-old E8400 gets 180fps on average.