(I have the X61t, which I think is quite possibly the nicest piece of kit ever. Silly mac users will never understand ;))
What is the CPU, is it LV or ULV and how is the battery life? This is the field where I find all of the existing notebooks lacking. I wish manufacturers have addressed this problem, at least used the existing ULV CPUs!
That said, I'm happy with my X60s, maybe it and the tablets are even the nicest pieces of kit ever, but they could have been made so much better!
Different tablets use different technology. The Wacom tablets use an inductive charge (from the tablet itself) to charge a capacitor on the pen. This means that yes, you need a special stylus. However, because of it, you can get much more precise location and pressure readings. You also don't need to change any batteries in the stylus, as it's powered "over the air."
Powering the pen does consume some energy, but I believe the panels used for TabletPCs can actually be classified as "Low-Power" USB devices, so the drain isn't nearly as much as, say, the hard drive. I'm not sure how efficient the Windows Ink code is, but our driver, which hasn't taken extreme pains to be performant, peaks at about 3% of a 1GHz CPU when the pen is in range.
Oh, nothing. There are two distinct questions of usability that I'm interested in. Except, that X60t tablet is different model form X60 laptop and may use different CPU and battery model, which of course impacts battery life.
The touch is really so-so, but mostly because normal desktop UIs aren't so good with such a large "pointer".
I think you have your answer for power consumption, but I think my tablet is in the same general range as your X60s and probably there will be more variance depending on usage patterns. My two batteries lasted a full day of class using onenote and occasional hops on wifi to download notes, etc.