I didn't have any trouble installing Palm Desktop nor did it create permissions problems. I agree that all of the components are dated. I have long since moved on from the palm components and I keep this around only for the iSync component.

Apple's iCal and Address Book pretty much take care of everything else. I do miss the nice skins that Claris' (and by inheritance - Palm Desktop's) old calendar had, the ability to put contacts in more than one category, and the ability to sort and filter contacts by different criteria. The Claris address book could even launch Applescripts. Why hasn't Apple brought that back?