1. Mainly the amount of vapor i get in a shorter time. My ecig is like a 3.4v I think and it just takes too long to hit. Also want better flavor and I've heard more powerful ecigs deliver flavor better. I'm vaping Blueberry and other fruity flavors.
2. I like the pen sized ecigs, so like the ego, but I like box mod style as well. I really want it to be a bottom feeder as well.
3. That I have no idea on. I'm no expert on the atty types. All I know is mine is a bottom feeder and want to keep it that way, dont know if mine is dual coil or what not, though.
I'm guessing, but i think you mean your atty's are bottom coil and not bottom feeder. The reason I say that is because when a mod is a bottom feeder it has a bottle of juice in the mod that you squeeze and feed juice upto you atty. Checkout the
Reo Mod and
Vmod for an example of that style.
If you want VV/VW and are cool with a box mod, that link above to an MVP 2 is a great deal. I have the MVP 1 and it performs as advertised and the battery lasts a long time between charges. Your atty's should fit on it no problem if they have a 510 or ego threaded connection.
If you want to look at inexpensive VV/VW tube mods, the Vamo, SID, and Zmax all have people who like them. With a tube mod you will need to buy separate batteries and a charger so budget accordingly.
The other option before you buy a new mod would be to try lower resistance heads in your atty. If they are replaceable, you should be able to find some replacements. With a lower resistance head your 3.4 will seem like a higher voltage because it will heat up the coil faster and hotter. Just a thought.