Personally, I didn't use PageMaker that much, and when I did it was quite a while ago. InDesign, though, is a great program in my opinion. It's managed to do a lot of innovative stuff while Quark has been busy just trying to get their software to work correctly. InDesign is definitely my choice for page layout software.
Also, from what I can tell, InDesign CS for PageMaker is InDesign packaged with some plugins that give it some PageMaker features. See
this page for details.