Has anyone used something like trimMail RackMounts or similar products?
Do they perform better than traditional and cheaper local software solutions in your experience?
Eg, a ClamAV/SpamAssassins combination?

Ever experienced any false positive with such specialized hardware gateways? This, as I'm sure we all know very well, can be very critical.
How about false negatives? This again is just slightly annoying, unless it lets through a large percent...

Anything else you've noticed?