did anyone compared the two?

I believe Alan has commented on this often, they are designed to basically have the same sound signature.

Can anyone summarize Alan's or their own interpretation of the sound qualities of each? Just recently seeing the frequency graph of the VP150 in a review, there is some separation that the reviewer was mildly concerned over. I do not understand what the separation means or how it would affect the sound (especially to my untrained ear).

I figured I am pretty safe having ordered the VP150, when I see so many with dedicated HTs using it with no negative comments. I assume it then to be the best CC choice for matching with M60s or M80s. Just curious of what that separation in the graph lines means.

As sirquack said, they are supposed to sound very similar. If you are considering both, I would suggest the VP over the W unless you really need an on wall installation. I personally have just purchased the W150 along with W22's and QS8's for my setup - installation happening this weekend! However for my HT room I really needed an on-wall solution with slim depth due to room entrance relative to speaker placement. The VP will allow you more flexibility to angle and tune the placement of the speaker whereas the W will be fixed where you install it.

Well I sure mis read! I was thinking Vp150 vs. VP100...
VP vs. W .... Ooooooooh! oops