I have only flown the AA-5 once and was impressed enough to consider buying one but was more impressed by the DR400 and have had two of those.
The AA-5 has a lot of minor problems that could become expensive, most of these have "fixes" and as long as these have been done the aircraft should be largely trouble free. This leads me to echo the advice that you should get any potential buy inspected by an engineer who has a lot of time maintaning these aircraft.