We've decided to update XKit. It's harder than it looks. We're not in contact with the original XKit Guy, nor do we have access to xkit.info. We currently operate at this blog and on GitHub.
I'm on opera, and I've been using the chrome version installed via the Download Chrome Extension for opera which allows installs from the chrome web store. Is there any difference between the opera and chrome builds, any reason to switch?
Nope, the Opera and Chrome extensions are exactly the same.