I am happy with Autoglym cleaner & conditioner - strange - but my 2010 4/4 sport still smells of leather(perhaps I do not drive it fast enough to alter the aroma of the seating!!!) - the first thing most people remark upon when they get in it. Mine is Muirhead tan leather.
I think Autoglym keeps the original smell but cleans & preserves quite well without letting the seats get slippery.