Thanks for the suggestions guys, I have some reading and searching to do!
@Kotta RE Bi-wire, I am only running a single run, and have it connected to the high frequency terminals. I have ordered some decent jumpers and when they arrive will move it to the lower frequency terminal to see if this helps, and maybe just try it with the manufacturer jumper as suggested.
@Erikt
My speaker cable is the AU24 and I'll be hanging on to that one. Yes I believed Marantz to have a warm character too, hence the AU24e interconnects. But I think my room is partly to blame, but I have done all I can (rug, heavy curtains) without taking over the downstairs of my place. Plus, the metal tweeter on the Paradigm Studio's (metal tweeter, quite a forward speaker) probably also contributes. But overall, very happy with the speakers.
@Philjolet - Agreed, however I did have a chance to hear the AU24e's in a much warmer system (Quad 606 and Kef's) and they sounded a lot better and quite neutral, but the AU24's really aren't suitable for forward / bright electronics and speakers at all.
@Mechans: Last night I did have a chance to borrow some v.old Cardas 300-B Microtwin's (which are a heap better than the current model) and they added some real warmth! Very musical cables, but I did lose some detail and soundstage, but I could live with it, (however they weren't for sale!).