my boxee is doing fine with standard definition vidz and xbmc would do the same,
for HD our hardware will always have probs on blu-rays and 720/1080-encodes,
remember it is a storage device, not a media player ...
Home Storage: 8x Seagate IronWolf NAS HDD 8TB ST8000VN0022 @ 608T
I bought a AS-602 recently and I used the boxee app to watch few 1080p movies with no problems at all!
I aggre that this is main a storage device but I find it very good as mediaplayer, too!
XBMC would be nice to have, but Boxee is perfectly fine for me right now.