Fortunately I'm lucky to just book with Avis regardless as the company picks up the tab and they are not too bothered about who I use unless it is ridiculously cheaper to use someone else.
But am I right in thinking that if you book with Avis BA you get more Avios? And with the new membership levels, do rentals / expenditure made with Avis BA count towards the Avis Preferred membership levels? (sorry if my question wasn't overly clear in the OP)