I don't actually use it that much for note taking, so can't advise on that specifically. I do use it for things like taking a screenshot and marking it up, and sketching out design ideas whiteboard-style. It works great for that, although most of the time I just use it as a conventional ThinkPad laptop.

In fact when I use the pen it is usually with the display hinge in "laptop" mode, not flipped all the way around to tablet mode.

Either way, as long as you have the software support you need, the hardware works great. It is both a touchscreen and a Wacom tablet with pressure sensitivity. At least the pressure sensing works in native Windows apps - web app support has been more spotty.

For annotating PDF files, I guess you would need Acrobat Pro? Or would you use some other software?