I bought the K200D over the D80(D60 checked as well) and e510. The important point was handling them first - the K200D felt better in my hands.
Also, my research suggested that the 4/3 system would be smaller (crop factor of 2 - see
Four Thirds System - Wikipedia, the free encyclopedia) which is a bit limitting IMHO.
As for RAW - its a bit of a learning curve to start with, but once you work out the workflow, its really fairly quick.
I use Adobe Bridge CS3 to classify my images, then ACR 4.6 (the current version) to adjust it (this is the learning curve bit), and finally Photoshop to tweak. There is some talk on other parts of the forum about the SilkyPix/Pentax tool - but I found it cumbersome compared to CS3 (I use that all the time at work anyway). I'm getting the other half to buy a rather good book for my birthday -
Real World Camera Raw With CS3
The other thing I noticed is that the JPEG straight out of the camera are really quite good - you just have to tweak the defaults a little to suit your style. JPEG by nature is lossy - so you will lose something. Its not as bad as the reviewers say, and it is
very subjective!
I shot a couple of night scenes recently on Pentaxium day (see in the gallery here) and found that with RAW I could get enormous recovery of information - at least 3 stops. Admittedly it was a bit noisy, but I could pick out the wave and beach in the image. Its a bit like push processing film (who remembers that?
) to get more detail out of it.
And if your worried, shoot RAW + JPEG to start with. There are lots of tweaks you can apply to the JPEG in camera. You can even part process RAW in camera if you choose.
As for frame rate - you have to consider what you shoot as Marc and others have said. Perhaps there is an action shooter around that would like to comment.
Good luck with your choice - but remember to handle the cameras first. After all, do you buy a car or furniture before trying them out a little?