WP 5.1 vs WP7


Gentlemen,

I have decided that I want a pair of Wilson Audio Specialities Watt/Puppies. I have been wanting them for years, but...
My budget does not allow me to buy new, so 2nd hand here we come.

The question is if the WP7 is worth 2/3 more than the WP5.1. The 7's I have on hand are (according to the dealer) mint with all accessories and Fly Yellow. The 5.1's have had the midrange changed (by authorized distributor) and have usual used item marks, but fully functional and standard black.

I lean towards spending the extra money and get the 7 - which I can have at very good price, probably due to the color (Fly Yellow). I will go course also have to live with that color in my living room for an extended amount of time :)

How big are the sonic differences? I am told that the 5.1 are hard in the top end - not really something I have noticed when listening to them, but then again I didn't listen with the intend to buy. I have only briefly heard the 7's here and there.

Thanks for your comments

Henrik
plafitracer
Love my w/p 7. Have no desire to upgrade unless it's for the new Sasha 2. Small foot print and extremely dynamic.
Now, 2 1/2 years later I am still a happy camper with my WP/6's and ARC tube gear, the VTM120SE's and LS16MKII. 
However, I recently got the idea of reducing the number of hifi boxes in the home, exchange the 5-6 boxes to an integrated with built-in RIAA and DAC. I have started listening to some of them, so far the McIntosh MA7900 and Vitus RI-100. I have to listen to the Mark Levinson 585 and Gryphon Diablo 120 next time, I am not convinced with integrated yet :)
So far they sound great, but I can't help thinking that a set of NOS tubes the ARC gear would be even better (and cheaper) 

I also consider going the Transparent cable way - where should I look, Super or Ultra?