I checked this with Wilson and they said
"The X-1 Series 1 is a design that dates back to the early 90's (1993-1994). With huge improvements having been made since the introduction of the X-1, my first inclination is to recommend the WATT/Puppy 7 for the best current sound of the 2 choices given.
However, the X-1 was our flagship for more than 10 years, which says allot about the ability of the X-1. To add to the value of the X-1, Wilson Audio is developing an upgrade which will push the X-1 up there just under the performance of the X-2 (not to say that the X-1 will be so close in performance that you couldn't hear the difference between the X-1 and X-2; the X-2 is far superior with it's aspherical group delay adjustment and it images better in every area). I can honestly state the X-1, with the Level 5 upgrade (available next year and has not been mentioned to the press, yet), will be the second best speaker system on the planet."
good enough for me.
cheers SR