To Each... I won't and do not (specifically) tell anyone not to use it. I'm stating my overall opinion of the Pentax software. The Pentax camera utility basically mimics what the camera does. If price is an issue or one does not have the desire to learn a more complex package, then I suppose the Pentax software is workable. I've never had an installation of it however where it didn't constantly crash. If it were my only option, I would just let the camera create the JPGs and be done with it which, a lot of people also do.
With CS5 ACR, I can load 40-50 PEF files, make my fixes, crops, etc and let it generate my JPGs. If the fixes are all the same (WB for instance) I can correct it in a batch operation and only physically make the correction with one photo and let it apply to everything else selected at the time. Then with the same package I can put my frames on, copyright, filters, whatever I choose to do.