I tried to use an SL-5500 for a while but got tired of the "rebooting without suspending results in a hard lock and lose all your data" bug. The last time that happened, I cashed in on my extended warranty and bought an Axim X3i, which I've been slightly less disappointed with (lately I just use my phone for a PDA).
It was good while it worked. I ran OpenZaurus (or Opie, or whatever they're calling it now), then tried the Sharp 3.10 rom, then theKompany.rom (which was the best) but they never fixed the biggest problems. It taught me that the reality of an open source device rarely lives up to the potential. As long as you remember to suspend at least once between reboots and don't do anything too exotic with it, I'm sure you'll like yours just fine.
I think I have a handful of registered theKompany apps for it still around (I paid for them) that I'm not using (obviously). Stuff like tkcEditor and maybe a game or two. If I can find them, and you want them, I'd be glad to give them to you.