if you want something smaller that is still vv/vw try:
http://www.innokin.com/itaste-vv-v3.0.html
small, uses micro usb, and has variable voltage or wattage in a smaller ego style threaded device. I use one and its great.
I don't use clearomizers though, I got inconsistent performance from them and I've tried a bunch. I just drip into boge cartomizers. I add about 2 drops and its good to go for a few puffs. Also its more conservative on the juice since you aren't fiddling with trying to fill a tank where alot goes to waste when cleaning, etc.
Edit: also be cautious if using flat-top batteries with the vamo. They can lose power connection easily with the top pole and cause severe annoyance when the vamo keeps shutting off since it takes several clicks to turn it back on. This was my experience, but others are reporting no issues.