As it happens I do most of my instructing on an AA5 at present - and agree, of that bunch, definitely the best training aeroplane. I'd still put the PA38 slightly ahead as a trainer - but as an aeroplane to own (which I partially do) the AA5 wins hands-down.
Not convinced I agree about difficulty getting a C172 on the deck, unless adding an unnecessary margin to approach speed, which a lot of American schools in particular seem to do.
G