Thanks for the info, guys... I've bought my chip from Best and it does indeed work without swapping OS and syncs fine with my monitor.
However, some games run noticeably slower (Yoomp! is particularly objectionable) now. Is there a (relatively easy) fix for this? I've searched the forums for posts related to ANTIC swaps, but I can't find an answer. The topic of timing issues is barely mentioned... am I just hyper picky?
Ideally, I'd like to have both chips in my machine and be able to switch between them. I know this has been brought up before, but again, no definitive answer.