I'm also interested in both these products. I've used Livescribe pens since the beginning - Pulse, Echo and then Wifi (Sky pen outside UK). HUGELY disappointed - no, frustrated - with the wifi pen.
Despite researching before purchase, wrongly thought the wifi pen would add wireless connectivity to the already v. good Echo. I preferred livescribe desktop app on my work pc laptop and personal MacBook pro, for organising my notes & notebooks. Wifi pen's exclusive use of Evernote only was a bad move. I DO use evernote, and it's good for what I use it for on all devices (work PC, MBP, iPad, iPhone, but Livescribe is woeful with Evernote. Searching abysmal, way, way better in Livescribe's own desktop apps.
And then there's the poor writing experience with previous livescribe pens - something that definitely appears to be addressed on the "3".
I've got BOTH on order, may keep the Adonit Jot Script purely for drawing and sketching-out notes on my iPad, whereas the Livescribe 3 pen will be for note-taking in meetings.
the other dilemma i face, is that having trialled dozens of "note-taking" apps, I've been using Beesy by BeesApps for about a year, and I have to say it's superb - using the Livescribe 3 pen would be a move away from that, so some serious contemplation to-do......