I got ropped into Blu Cigs solid marketing campaign as my first E cig. Once I was quite aggravated at its lame vapor output and tiny cart buckets, I tried the 510 and a 901 that everyone loves. Damn fine vapor production... but my cheeks felt like they were going to cave in from sucking... Thus, I found myself falling back to the Blu Cig cause of its ease-of-draw, size and weight.
Then I tried the 4081 for a little while, but found myself falling back to the Blu for almost the same reasons (I bought it cause it fits in the 510 PCC).
Then I tried the 306a for a bit until I realized the atty fits on the Blu. Once that happened, I was in heaven. Nice solid vapor production on my cig sized Blu.
Then I tried a Modern Vapor sidesho, but didn't like the sensative batteries and the fact you can't fit carts with an atomizer in each hole (only one space fit a cart+atty, other were just carts). So again, I found myself falling back to my now vaporlishious Blus, but with some really awesome compatible parts from the Modern Vapor Sidesh.
It was around this time that Volcano (same as Blu Cigs but red) started to sell the carts with SUPER BIG cart fluid buckets... so now that the 306a solved the vapor production issue... and the new carts solved the tiny fluid bucket issue...
... I settled on the Blu and Modern Vapor SideSho as my go-to ecigs (now that Modern Vapor has manual batteries). The SideSho PCC I use only the one space for its default cart+atty. The other spaces I use my Blu atomizers/cart since the SideSho batteries seem to actually work better with the Blu attys than the Blus do, not to mention the cart+atty fits like in the Blu PCC. I have a plethora of both Blu and 306a atomizers which fills all slots for both PCCs which I carry around with me. I figured it's not unusual for an anolog smoker to carry two packs... why not with e-cigs too, right?