Jailbroken ATV2 will read a NAS drive as well, which allows it to overcome the one thing an ATV1 has over it, no storage. I have been running a Jailbroken ATV2 for over a year with Firecore on it and have been very happy with it. I have XBMC on it, but Firecore's media player is pretty basic (but works great), which allows my girlfriend to use it easily. Her computer skills are pretty basic, and it has a few less steps than using XBMC.
2011 iMac, MacBook 2.4 ghz Black, iPhone 4