I use an Acer TravelMate C300 tablet, and have had it for over 18 months.
Great system and pretty reliable (although I did have a hard drive
failure for the first time in 10 years).  Once you get comfortable with the handwriting recognition software in Windows Tablet, you will love the system. 

The screen on the Acer is a full 14" diagonal screen - larger than the ones on the HP/Compaq and IBM/Lenovo units.  If you use the tablet as your primary PC, as I do, you will want the larger screen, especially when you are out of the office.

Make sure to buy the extended warranty!  You may be sorry if you don't.

Stephen Marcus