I have to totally agree with DDark, if you think a twist is to much or to big, theres not much of an upgrade to be had (thats what MOST people upgrade FROM). I would say you seem to want to keep the smallest form factor (808 automatic "Cigalike"), so my suggestion is just find some good juice and cartridges or pre filled cartridges that you love and have the GREATEST vaping experience.......for YOU.
Good day.
I have a 1000mah ego twist as well, it's not that it is big, but it is looong.. By the time I put a clearo with a drip tip on it the whole setup is about 8 inches long, which makes it impractical to carry in a pocket and abit hard to conveniently carry at all IMO. Great for around the house though. I just end up breaking them if I am working and such as I have no place to put em when I'm working on stuff outside for example.
Something unbreakable and under 6" rides in my pocket real easily. The ego-T is a good balance for battery life vs size, the mini nova is a good balance for toughness and capacity of juice (with the aluminum tank) and for keeping it under 6" long. Someone who doesn't vape as much as me might even be better off with the mini ego 350mah bat and get the whole rig down to about 4" long. I require more battery life than that though.
I also had some issues with the plastic clearos with the clear plastic tank breaking down from some juices, it seems to be brand specific, the clearos from one B&M store near me broke down from juice badly, the clearos from the other B&M near me did not, and were significantly better made, though to an untrained eye they look identical. For me the aluminum is the answer as it won't break down and won't break from dropping it on concrete either. For others who aren't going to be so rough physically on equipment a decent clear plastic clearo would be just fine.
In fact if someone really preferred a clear tank I would not recommend the Mini Nova as I really do not like plastic threads on the clear mini nova tanks, they are inherently weak, and will eventually wear out even with the utmost care. Of course they can also be replaced at just about $3 a tank, so it's not that big of a deal.
Many of the clearos have metal on metal threads for the tank, which is always more strong and durable.