I like the 6000's very much. they do, in my opinion, an excellent job of complementing the 3005's center with the balance of the 3005's as surrounds. I haven't wall mounted these as of yet but with the select-a-mount system integrated they're quite flexible for that. The only pic I have is from the unboxing (I originally picked up Polk 75T's for fronts but those were disappointing on the Yamaha RX-V673 - I had to bi-amp the 75T's to get them to sound good and I'm not losing 7 channel and zone 2 just to use the Polks.)
There are times the bass cutover hasn't kicked over (a problem I'm seeing quite regularly on the Yamaha RX-V673 that I'm quite displeased with) and the 6000's do a respectable job of having you think the subs are at work when it's the 6000's you're actually hearing.
To be frank I couldn't see a 5.1 setup of the 6000's as they're two feet tall, the 5005's would provide the signature KEF sound in lower profile and richness, just I had heard they get strained at higher volumes.
Me personally, having the 3005's and the two 6000's I had no compelling reason to pick up the 5005's even at the sweet price mentioned (which I think is now expired - keep checking kefdirect.com and accessories4less.com (KEF authorized re-seller.))
accessories4less.com has the black KHT6000 for 250 at this time. To say the silver ones I have stand out is an understatement with the black 3005's and my panel, but it's the sound I'm really after...