I've been using XVim for over a year now and it's been reasonably stable. They have an issue with code folding but then I don't fold while the plugin is enabled.
Fwiw. Folding shouldn't (big shouldn't) crash it but navigation is not like vim is.(the cursor is hidden inside the fold while you do navigation stuff. It eventually moves out of the fold though. It's on my list of things to fix with xvim.