@Silver unfortunately I haven't gotten around to getting a Drop version, but I'm going to assume that the trade-off between the two is basically larger tank and cooler vape (on the standard) vs slightly improved flavour and a slightly warmer vape (on the drop) due to the shorter chimney. Of course I can't say this 100%, but it is what logic suggests 
As for mouth to lung, the airflow (on both) can be closed of almost completely (basically like a kayfun draw) so it works just great that way - I've also found that with the airflow open I can cover two of the four airholes (with my fingers) to temporarily get a tighter draw
All-in-all I really think it comes down to tank size in regards to the choice between these two. For me the convenience of a 5ml tank is what makes the RTA shine - for flavour a RDA would still be better I suppose, at the cost of convenience. But maybe the Drop vesion is a happy medium.
I'm sorry this is a non-answer actually, I'd definitely need to try the Drop version to compare, before I could say for sure
Bottom line, I think you'd probably be happy with either as is evidenced by my enthusiasm for the standard version and @eviltoy's love for the drop - i.e. this tank, no matter it's size does not seem to dissapoint
As for mouth to lung, the airflow (on both) can be closed of almost completely (basically like a kayfun draw) so it works just great that way - I've also found that with the airflow open I can cover two of the four airholes (with my fingers) to temporarily get a tighter draw
All-in-all I really think it comes down to tank size in regards to the choice between these two. For me the convenience of a 5ml tank is what makes the RTA shine - for flavour a RDA would still be better I suppose, at the cost of convenience. But maybe the Drop vesion is a happy medium.
I'm sorry this is a non-answer actually, I'd definitely need to try the Drop version to compare, before I could say for sure
Bottom line, I think you'd probably be happy with either as is evidenced by my enthusiasm for the standard version and @eviltoy's love for the drop - i.e. this tank, no matter it's size does not seem to dissapoint
