@B Mitchell - Thanks for the advice. I think you're right. I was surprised at the price of the US 6Ks that were being sold recently. (https://www.meridianunplugged.com/u...bb=showflat&Number=142451#Post142451)

I'm using 3x 5200s at moment with G68 and Squeezebox touch. So maybe the upgrade cost won't be to high!

@Carl - Thanks for the pointer!! I found the centre 6K on second look - it looks less space age then it's brothers!
http://www.Meridian-audio.info/viewphoto.php?compid=4&photoid=237

@DPAWS - I can see the logic behind your thoughts; do you have a feel for the ideal minimum sized room for 8Ks (do I need to move house?!)

Cheers
Tom

Main: G61SL, 218, HD621, 2*7200SE, 7200HCSE, M6s, DSW, Apple TV 4K, NUC (Roon server)
Secondary: Wiim Pro, 3200, Audio Core 200
F80