Q: For example, does the A3000 have the leaking battery issue?
A: Most do by this time. Mine did, but was recoverable. Definitely a #1 thing to look at when buying used...
Q: I seem to remember hearing something about the Buster chip revision, but not sure what the issue was.
A: Can have some issues, but really, you don't need to do anything about this. You can still use a DENEB or Zororam, configured correctly.
Make sure the flicker fixer is still in working order (one of the unique reasons to collect an A3000)!