Until recently, I've been using Olympus gear almost exclusively. Probably had about 10 bodies, but currently only have my original - E-1 (still the best). I've used OM, K mount and Nikon mount lenses on the bodies with good success. To be honest, I find the legacy glass experience much more enjoyable on my K200D than I ever did on any Olympus body - including a Katz Eye equipped E-420. The focus confirm and bright viewfinder at all apertures make the Pentax experienc much better.
Not worth it in my opinion. If you want to grab a hold of some of the amazing digital Zuiko zooms, that's another story. Boy I miss those.