As with most consumer products, especially vape gear, it all comes down to personal preference.
As far as the tanks you mention, I have a Baby Beast, Big Baby, and a couple Herakles. While I like the flavor in the Herakles, I use the Beasts far more due to good flavor and more "user friendly." You state you are using the Baby Beast, but not if you are satisfied with it. If you are, the Big Baby. If looking for something better..... eenie, meenie, minie, mo.
Other suggestions? I also use TFV4's and a TFV8 and like them all.