Originally, I did plan to buy an eTrayz but then I decided to monkey around with a HTPC - try out XMBC, see how it does with PC games, etc. It did not do too well. The PS3 does games much better, and the XTreamer is still a better media front end IMHO.
By the way Bro, our XTreamers play media stored on the other regularly without any kind of problems. The connection is a wired one but they are separated by a Belkin N150 router. Oh and these are, more often than not, full HD files 1080p (8Gb or more). Maybe you are using a wireless LAN. Our system had hiccups too when I did this, and there were other issues as well, so I just wire them.
One thing I am annoyed with is always having to remember on which XTreamer and which drive I put which. Another is deciding where to put new files. A single server would solve these issues.