Me again. I've been using Appbox on three Macs and now feel I've had enough experience to accurately rate the app.
The thing I like most about Appbox is that it provides an excellent way to roll back to previous versions of Mac App Store apps (on Macs that don't have Time Machine enabled). When I download apps from MacUpdate or anywhere else, i always keep a copy of the DMG or ZIP of the previous version, so I can roll back in case there's a problem with the new version. There's no simple way to keep copies of older versions of MAS apps, so it's Appbox to the rescue.
What I'd like to see improved is the ability to selectively restore the app bundle, a plist file, app support folder or whatever. I used Appbox to restore an older version of a MAS app that had a bad crash problem in a new version, but I had to restore everything, overwriting my newer plist prefs file. It would have been better if I could have chosen to restore just the app bundle.
Some better CPU management would help, too. The last time I ran Appbox I thought my 2007 MacBook Pro was going to self-combust it got so hot. A "zip" process seems to be the main culprit, but for some reason Appbox also makes Spotlight and Dropbox go wild, even though I'm not archiving to my Dropbox folder.
As I mentioned in my previous comments, scheduled backups would be welcome, too. Appbox has a lot of promise, and I hope the devs can add some more features to make it an indispensable app.