i think they're both about the same in terms of vape/flavor, after all, iirc they use practically the same
coils..the only thing the Aero has going for is it has an adjustable airflow valve. IMO the protank 3 mini is more airy, for my preference i had to cover up one of the holes.also, the protank mouth peice doesn't fit as solid and can wiggle a bit. not a big deal i guess, also price is a pretty big factor.. $7~ vs $20+ (i've seen some sites selling the aerotank for $28~ which is insane when you compare the difference between the two clearos)
i think a good option is if you already have a protank 3 mini just buy the air control valve which is around $5-6 and you'll basically have converted your protank 3 mini into an aerotank.