I also have the AspireRevo 1600.
It generally works great with XBMC, but if you are going to play a lot of 1080p content, you might be better off getting a dual-core atom. 1080p videos play fine, but there can be some stuttering if you have background processes running (like sabnzbd), or if you need to do any audio processing (like software mixing).
Since the AR1600 comes with windows XP, I first tried XBMC for Windows, but it didn't have hardware accelerated playback, even with the latest nVidia drivers. I installed an ion-optimized version of the XMBC live cd (based on Ubuntu Linux) produced by XBMCFreak.
The AR1600 also doesn't have any digital audio outputs, other than HDMI. This means that if you want surround sound and your receiver doesn't support hdmi audio, your tv needs to do digital audio pass-through.