I use XPe, and while it's missing a couple of bits that would have made my life really easy (it doesn't work with our VPN software, although I don't like Checkpoint much anyway!) it's been a cinch to put in on the floor and we've got around our difficulties through using Secure Gateway on an internet-facing page to get around our VPN issues.
I like it, and while I'd love to mess around with a couple of CE terminals and Debian Linux jobbers, the powers that be want Microsoft (ruling out Linux) and a couple of the other guys in Networks have raised questions with CE particularly with regard to printing.
Very easy to deploy in a 2003 AD environment, and not exactly difficult in our 2000 AD - just a couple of the new features need registry edits to be amended rather than GPO.