Not the 3.2, but I have owned a 2.2 Spider for a few years.
The main issues common to both I believe, are things like rusting to the front subframes due to water being trapped by the engine shield and electrical gremlins often triggered by a flat battery.
Check the windows switches work well as they are a weak point.
Both cars are heavy, especially the 3.2 lump and therefore the top and bottom suspension control arms often need replacement.
The 3.2 certainly makes a lovely noise but neither is really a sports car - more a stylish GT?
Early 3.2s tend to be 4 wheel drive adding to the mass, but front wheel drive was also available.
Had they been RWD like the latest Giulia, I am sure they would have been a greater sales success?
One concern is Alfa have stopped supplying spares now and so you may be dependent on salvaged items and all that entails.
A Brera at least does not involve any worries about the folding roof failing!
Finding a car without severely scratched dash and aluminium interior trim panels is rare, as keys and any jewellery tend to dent the soft metal trim.
The later fake carbon fibre trim is probably hardier than the aluminium.
I suspect eventually, many cars will have their interior trim panels painted instead?
For future classic value, I would say the 3.2 is the one to go for, but unfortunately it is not the old Alfa Busso unit.
It goes without saying a 3.2 is not one for someone concerned about fuel economy or low emissions.
For anyone wanting a lot of car for the money with some Italian style thrown in, I would say they will always put a smile on your face when you look back at it.