On the needing to turn it louder... Now... I'm not saying anything to the Model 6s specifically. Never heard them and overall I respect Cambridge Soundworks...
I found that cheap and heavily coloured speakers sound "fuller". I find that clean uncoloured speakers lack the same presence, seem thin and need to be turned up higher to sound like they fill the room. They could be said to be metallic or brittle as well.
If you are used to, and enjoy, that "full," "warm" sound, Axioms may not be your cup of tea.
Having said that, I've never heard the CS Model Sixs and I could be wrong.
my 2 cents
M22, VP150, QS8 <--all v2
Sub: Outlaw LFM1-Plus
Denon AVR1910, Panasonic Plasma 50" S2