I have been using ego style vv with bottom coils when out and about, which is a lot. I just do not want to schlepp a lot of the paraphernalia with me associated with RBA's when travelling. The BC's satisfy my inner drive to mod and yet are a real easy swap of a burned out coil in the field.
My ego's are not vw, but at the market prices of the itaste vv, it was just not worth it. Comes Black Friday................and I saw them on Vapor World for $29, so I bought 2 and an MVP 2 at $39. I have the SVD from Innoken and was impressed with the quality of that unit. They arrived today. I have only had them for a few hours, but I must say that I am impressed. These are version 3's.
My cell phone, headset, and Kindle are all micro usb, so this is one less cable I have to worry about. The retractable cable supplied with the unit is really nifty. Such cables are around $5-$10 as stand alone items.
The pass through is nice, although I would never hook up anything to my PC to charge. I am also impressed with the MVP 2. That came with an Iclear 30. It is certainly better than the other top coils I have tried, but I prefer my modded Kanger's.
Overall, I would give this a 9 out 10. If they made a mod with 4000 mAh in the same size, I would give it a 20/10. It packs a lot of features in a small package, but at 800 mAh, I just wish it had a little more staying power, but that is a limit of the battery technology more than the device. If you are a chain vaper, that is not a lot.
Still, it's a great little unit.