Oh yeah - I used StarOffice 5.2, and 6 beta, and now I've switched to OpenOffice. I haven't used it a lot yet, but here's my impressions:
1. Cost: FREE! (Can't beat that!)
2. Looks & acts like MS Office (much better user interface than SO 5.2 had)
3. Ability to open & save MS Office files (maintain compatibility while changing to new platform)
4. I think it can natively print to PDFs, too (?) <-- (I use Redmon & ghostscript to setup a PDF Printer on my system, so I haven't bothered with OpenOffice's version).
5. Open-Source: Much more clear what's going on with the project than MS Office
6. Size: <100megs (install file) vs MS Office's, what, 6 CDs now?
Over all, I'm very impressed - it's a free product that has all of the functionality of MS Office (to my knowledge), and the nice interface, without the bloatware, delayed updates/bug-fixes, and expensive licensing.
I'm actually curious to know if anyone has found something MS Office is actually better at than OpenOffice?
Edit: Now that PrincessGuard mentioned it, I did have some issues converting MS Office documents to SO 6 beta & back... so it's not perfect yet. I haven't used the find..replace feature, so I can't comment on that.