Vandersteen 7 mark ll or big Kef blades

Your ears period .With such a large outlay it's critical.

Per several dealers and people I trust the Blade 2 is the better speaker overall than it's big brother and it compares performance wise with the Quatro and maybe the 5A.  Don't think it is even in the ballpark of the 7 Mk II other than cost. But as most every other poster has said get out and listen for yourself as in this price range it is worth the price of a plane ticket if necessary.  

OP - You are getting sound advice from those posting above. Trust your ears, BUT... settle in and listen for a l o n g session.  Which speakers make you want to stay or keep a smile on your face.  

I have no experience with the Kefs but have owned Vandersteen's for the last 30 years.  I just go into my listening room and enjoy the music.  No "hifi" from them.  They just play the music.  Oh, and I smile a lot!🎼

With thirty thousand dollars of distance between (not considering the difference is typical amp pairing) them I have to wonder from a marketing perspective why these two particular models are of interest.

Tannoy Westminster Royal