For quite awhile I've been using an AppleTV (version 2.4) box with a 1TB external USB drive and XBMC. Recently I updated to 3.0.1 which required the hack to be applied again. So rather than just put XBMC on the box again, I thought I would look at alternatives.
I decided to look at Sapphire
I installed Sapphire and I'm quite pleased with this program. Relatively easy to install and configure. The apple like interface fits in quite nicely with the Apple UI. Grabbing metadata from TVrage.com and IMDB.com works quite well - get show descriptions, artworks, etc.
What I really like is the gem icons that let you know which shows you have already watched. Blue gems = not watched, red gems = watched. Also, there is no waiting to launch Sapphire like there is with XBMC.
I've now switched from XBMC to Sapphire. The viewing experience is much better with Sapphire and I'm enjoying my AppleTV twice as much. I can only say nothing but positive stuff about Sapphire, well not really....
Caveats and Cons
Sapphire uses the native Quicktime player to play your media. Therefore you'll need to install codecs (such as divX) that AppleTV doesn't handle. I first tried Perian but had problems with it crashing when Fast forwarding and rewinding. So I installed the divx codec from divx.com and it works just great!
Some menu items in Sapphire don't seem to work 100%. For example, scan for new files doesn't seem to do anything, you'll need to go to Setting and select import data when adding files to the database.
Only uses tvrage.com to get show information. Would be nice if it used thetvdb.com as well. As well if Sapphire can't find metadata for a file it will not show up in your tvshows (it can be played, but it's a bit inconvenient).
Anyways, anyone using AppleTV with XBMC might want to take a look at Sapphire - it's a solid little program.