Yum. Actually, one day many years ago, I put on my best suit and combed my hair and went test driving fancy cars at the various lots around town. I actually liked the 140 better than the XKE. Seemed a little more direct, less insulated, even though the XKE is faster. I've never been in an XK-120.
Honestly, I'd trade every bike in the basement for any of the 3.