Well, not to brag, but I sincerely doubt there are many stylus solutions I haven't tried. I have had multiple tablet PCs and UMPC devices, multiple tablets from Wacom and Genius, and there's a Cintiq 12WX on my desk. When I go outside, I have a Vaio UX and an iPad in the same bag. Crazy, huh? But no, that's me, and it's not really relevant to the discussion.
And that's part of why my personal stance is that a stylus input, as an add-on benefit, doesn't necessarily make these tablet devices any better than what they actually are.
To be more precise, it's that I don't really see how being able to use a more precise pen will benefit the iPad, or Motorola XOOM, or... Blackberry Playbook, or the HP TouchPad. All of these devices are very limited in hardware performance. There are things my iPad would subjectively outperform other computers, but drawing is not one of them.
Just imagine using Photoshop on something that is 10x slower than a netbook and you'll see how bad it actually is. Software just isn't there, and neither is hardware. Most drawing apps are limited to the native resolution of the screen as an additional insult to your artistic ambition.
As for the pen and paper feel, it's only natural that it doesn't feel that way because you are drawing... on glass.
You may think otherwise, but I'm all for more precise pen input. Heck, I lug the 12WX around whenever I feel like it since it's portable enough. I just don't see how the "mobile" hardware of these tablet devices (not to be confused with tablet PC) will be able to handle the workload of a precise pen. Maybe note-taking wouldn't be too bad, but you definitely won't want to draw Mona Lisa on this.