Billfox--
I have been using a Motion Computing tablet and a Lenovo X200 tablet (got both off ebay pretty cheap.)
they work ok -- but I keep looking for something better.
I have been using a combination of handwriting recognition-- which is pretty slow and frustrating, compared to just writing on paper-- and templates to enter easy stuff into the AC boxes in the patient room, and I take more complex notes (handwritten) in OneNote which I save as a PDF file at the end of the visit. I pull that file up later as a crib sheet when I dictate (with Dragon) into the final note.
So I keep OneNote and AC both open in the tablet and switch back and forth. Works OK, takes a little practice, and if you get distracted you can get off track.
There isn't much in the way of "dropdown menus", but it is easy to create your own templates, and they are easily customizable on-the-fly so that notes don't always read like they came out of cyberspace.