Oh yes, it's my default dash after trying lots of others. Media streamed via SMB couldn't be simpler. Choosing video regions for games now also works perfect in xbmc...
The only thing I don't rely on XBMC for, sadly, is xbox-to-xbox transfers, where the built-in file manager has failed many many times to make a good copy of a game folder to another xbox. I still have to use the xbftp client... bummer at lan/system link parties, but usually no bother otherwise. And the file manager has some other issues too, which leads to frequent use of boxplorer, a sometimes better option.
XBMC 2005-12-23