Improved feature? What would that be?
In general, with the rest of factors remain unchanged, shorter tank=warmer vapor (especially under TC)
shorter tank=better/denser vapor
If you own both, e.g. TFV4 and TFV4 mini, you will easily notice that.
Also that isn't an Augvape product.
How do you know?
I read th article, it is a serious comparison with tables of details for all the 4 RTA. Augvape Merlin is a cheap tank but what has been discussed in the article is not.