Anyone use this product? we currently use Mantis and will continue to mantis, but we have a client who is looking for a recommendation from us on Fogbugz vs Mantis. i can speak for the mantis side of things, but i have never used FogBugz.
If I had a client who asked this I would get a copy of Fogbugz and compare what it could do and what if offered against Mantis.
I have not failed. I've just found 10,000 ways that won't work" --Thomas Edison
I don't believe that would be a good way to go. One day/week of demoing a piece of software does not equal someones perspective in using the product over time in a production environment.
I haven't used FogBugz, but have heard very good things..
(and I am fan of Joel Spolsky)