Michael,
I don't think the MS filters in "OpenOffice" are as good as the ones in StarOffice (6.0). This is, after all, one of the reasons Sun wants to/will sell a commercial product. I've got SO 6.0 (for some time, the final, not beta ;-) ) but I can't say how good it is, I haven't had to export any powerpoint stuff. I never had any trouble importing MS Word files though.
I'd noticed that about the filters when I had the beta version. I also noticed that the postscript/pdf output is better in the SO6.0 beta, have you noticed this with the final version? With the MS Word files have you had problems with OO where you have not had problems with SO6.0? I've been using OO for a couple of weeks and I have found that it mangles the formatting of my files a little bit and its depressing me slightly - today I installed cross over office and started running Office in Linux. It works well but if SO 6.0 does the job then I would rather go with that than running MS Office. Another thing with SO6.0 do you get the windows and linux versions for the one fee or do you have to buy them separately? Thanks, Jethro