I'm installing Windows8 Build 7850 on my Tablet PC and I was wondering if anyone had experience with 7850 on a Tablet PC.

I would imagine it would be exactly the same as Windows 7 on a tablet PC since no one has managed to unlock Immersive in builds prior to 8102. Specs and more details on the tablet?

The tablet is a Dell Latitude XT, with ATI Radeon Xpress 1200 series graphics, a Core2Duo, 3GB RAM, 120GB HDD, and N-Trig DuoSense Touch layer.

It should be the same as windows 7.the only features in 7850 that can be unlocked so far are ribbon explorer, advanced task manager, pdf viewer and webcam capture.
no immersive features as far as I know

Okay, I installed it and all my drivers, I found some interesting things/bugs:

A) The trails for when you move your finger(s) around the screen were already implemented this far back.
B) The Tablet PC Input Panel is "metro-ified". It also has smileys integrated as well.
C) Touch input is shaky, but pen input works like a charm. (I was expecting this.)

I've only had experience with 7989 on a tablet PC which was my Dell Inspiron Duo. I don't think there will be much of a difference except 7989 had the new keyboard and UI (Desktop; not metro)

Well, this is 7850 we are talking about.

Well probably it had Tablet PC option integrated to test it on a tablet itself.

this will work fine, i have a Release Preview build on my tab. (dunno the build number

I have too The Release Preview Build but its doesnt work it comes an error and i need restart the Computer