I received my JotPro yesterday. Up 'till now I've been using a Boxwave stylus.
First impressions:
I was prepared to really like the Jot. The tapping sound is somewhat distracting for me but I'll probably get used to it.
Used with hand-writing apps like NoteTaker, Bamboo, etc the Jot is fantastic! Precision is so much better than the Boxwave as to make them non-comparable. The Jot wins hands-down!
When using most other apps that require no sketching but lots of tapping then I prefer the Boxwave. The silence makes the Boxwave a winner, especially when using it around other people.
My personal opinion now is that I'm glad I own both as I will be using both, each for that task each is most suited to. It's not a case of one or the other, but each to it's own speciality.