Don't know about the X1 Tablet since don't know anyone who owned one (seemed a very niche product)...
Anyone with actual experience on this?
But in general, Thinkpad Tablets (X230T, etc.) had driver troubles with some of its non-keyboard buttons after an OS upgrade.
Not sure of other computer brands, does their tablets have trouble with OS upgrades?
I myself would love to have one of these X1 Tablets, primarily for its projector capability...
(But budget constraints prevented us from doing this, and X1 Carbon Tablets were slightly less powerful than its X1 Carbon notebook equivalents, given the same price budget range).
X1 Carbon 4th Gen (X1C-4): i7-6600U 2.6MHz; 16GB DDR3 1866 MHz; 1TB PCIe-NVMe; 14" WQHD 2560x1440; LTE EM7455 Mobile Broadband; Win7 Pro 64bit
Current Thinkpads: X1C-4, X1C-3, X250, X230, T410
Retired Thinkpads: T42, 560 (circa 1996)
Also: IBM Thinkpad era computer bag !