Just switch your existing Aerotank base onto your Protank 2, but use your Protank 2 coil on the Aerotank base, as the dual coil Aerotank coils won't fit because they have a longer base sleeve [presumably to accommodate 2 coils one on top of the other], and hey presto you have an adjustable airflow Protank 2. This makes the Protank as good as the Aerotank IMHO. I've never noticed much of a difference using dual coils, and recoil my Aerotanks with a 2 ohm single coil, same as the Protanks, and still get a vape I'm happy with.
If you then find you prefer the Protank 2 with adjustable airflow [as I think you will], you can then purchase an adjustable base for the Protank 2. Vapegear do 'em for £2.99, which is a pound less than myepack.
The other benefit of the Aerotank base is that it is solid, so no more liquid leaking onto battery contacts.
To be honest I prefer my original protank over the newer generations, none of them are bad and I enjoy it when ever I am vaping with a Protank/2/3/aero. I like the Aero for vape quality but I find it a little noisy to use, probably sounds strange but the draw seems loud!!
I hadn't thought about swapping the bases, I do like the solid base for no leak vaping. I'll definitely give it a go.
Apologies for hijacking the thread!!