The thing you want to look out for is "Will you need a hard disk?"
Both The sharp rom and Other roms can be upgraded to use other PIM applications. The thing you've got to realise, is that since SL-5000d, the Zaurus was never deigned to be a PDA, with great PIM apps. Sharp's niche is for a Corporate device, which can VPN into the corporate network, VNC all their existing computer systems, run full productivity suite, and basically be everything PalmOS and WinCE devices AREN'T.
If you get a Zaurus, I doub't you'll regret it, and if you do, change the OS! There are hundreds of ROMS, and even a BSD or two out there.
Just get it. Now to decide, do you want the hard disk? I warn you, having the hard-disk gives an insatiable craving to copy movies and PSX games onto the Zaurus. Both of which you should of course immediately do.
My 2 pence.
Ferret.