I use MacFuse on Snow Leopard daily at work and home and the worst I've ever seen was TextMate move slow when I woke from sleep (and the drive wasn't mounted)
This warning is much clearer (and useful). I completely agree -- disk-heavy moves can be painful.
On that note, if you're using TextMate with MacFusion/SSHFS, you'll want to get the ReMate plugin. It disables refresh on regaining focus for TextMate: http://ciaranwal.sh/remate/. No more beachball when you bounce over to the browser for a second :)
I use MacFuse on Snow Leopard daily at work and home and the worst I've ever seen was TextMate move slow when I woke from sleep (and the drive wasn't mounted)