I have been trying out the eGo Mega Cylinder Cartomizers (2.5 ohms) and the Cylinder (Type B) Mega Atomizer (2.15 ohms) and Mega Cartridges on standard 650 mAh eGo batteries.
The cartomizer seems fantastic at first. The double mouthpiece plug design is great to keep juice out of one's mouth. After taking out the two plugs with a hooked paperclip, filling with a needle is not very complicated, just don't forget to pull out the needle between rotating into different areas of the filler to distribute the fluid, or you will be tearing/shifting the filler as you turn. I have been getting close to 2 ml in without any dripping out. My first carto was filled with a 48 mg Camel juice from MFS and that was great. But with a milder flavored juice I realized there's a burning something (plastic? paper?) taste that never seems to go away. My second carto gave such a foul burning taste on a pre-fill puff I didn't even fill it. They are shipped wetted but the problem wasn't the wetting fluid, something was burning. My third was filled with 2 ml of Premium Tobacco 24 mg from ecigexpress. That's when I realized the burning taste is there even in the first one, where it was being masked by the strong flavor.
Pulsing the button does prevent the snap-crackle-and-pop of burning filler. It's clear you have to top off occasionally to keep it on that fine line between gurgling and incineration. I've been topping off my first one with say 1 ml of fluid a couple times a day during the two days of heavy use. Considering the huge clouds of vapor, it's not surprising, but it's not what you might call an economy vape. Carto number three, on reflection, tastes like crap. The burning whatever taste does not go well with the mellow Premium Tobacco. And who wants to inhale that anyway, masked or not?
Disappointed in the cartos, I turned my attention to the cylinder atomizer + cart. Wow, there's some artillery! The supplied cart filler is too narrow and pretty loose-celled, so I would expect it to leak. I tried a number of mods, including a Zero Fill silicone top cut from a cap. Cutting it to fit with a razor blade is quite challenging. Hard to avoid cutting some poorly fitting areas that will leak. The material is too thin, so it buckles and cannot contact the bridge, even if you do manage a tight fit (with practice) (you will by then have consumed most of your caps). It's clear that with such a wide mouth, the standard tricks won't work well, because you can't count on the fluid's surface tension and viscosity to hold the holy fluid in, the way it holds in a 510 cart with a minimal cap of filler.
Finally I tried a fine 000 steel wool. Washed it well, press-dried it with a paper towel, and formed a packed plug that was shaped better than the original plastic filler. Dripped some 1.5 ml onto the steel wool and inverted it. No leaks so far, no problems. Pressed the cart in place. Pulling it out, it was clear the bridge was nicely nestling into the steel wool, metal mesh against metal mesh. By the way, it's important to note the orientation of the cart relative to the bridge, maybe mark it on the plastic or just pay attention, as the bridge pushes the steel wool in and creates a perfect little nest of heavenly wicking for itself, so you want to return it to that same orientation when you replace the cart.
I settled down to watch a movie in HUGE blissful clouds of vapor. Incredible! OK, yes, there is a bit of gurgling, but I agree it signals profoundly powerful wicking, and while waiting for Joye to design a better air inlet, I'm OK with a bit of sound. Raising the end of the battery does make it subside, that and drawing a little less gargantuan puffs. You really don't need them, this thing is a bazOOka. After the movie, I added another milliliter, that was many hours ago, and have been happily vaping ever since. It seems you can get a full 2.5 ml in there, if not 3. When the gurgling fades, you know it's time to top off, about 30 drops brings the wool to a slushy look. Bam. Back to HUGE & THICK clouds of contentment.
The steel wool could rust after a while, and is known to shed, so it will be replaced at the earliest convenience with its 000 Brass Wool cousin, a material that is widely used for scrubbing boats. Brass wool is more malleable and doesn't shed sharp fragments like steel wool. There is also a Stainless Steel Wool, in rolls. I'm not sure which metal is best, there are many considerations, and plain steel is probably the worst. But Steel Wool is likely safe enough to try for a bit if you have some on hand, since after packing, shaping and trimming, the steel wool filler shows no sign of shedding, especially wet, it won't rust immediately in a propylene glycol solution, and the design of the mouthpiece makes it very difficult for any particles to reach your mouth anyway. Poly filler sheds worse, but you can take off the mouthpiece cap and put a tiny piece of loose cloth or cotton in there to act as a particle filter, if you're the nervous type.
I'm very happy with the Mega Cylinder Atomizer, and quite pleased with this Cartridge "mod". I'm afraid this might become my preferred vape-tool, "afraid" as it does vaporize juice faster than a 510 rig. But then, after all, isn't it what we do this for?
As to the "mod", one can pack the metal wool just right so the liquid wicks freely yet is held in place by surface tension, like in the smaller carts. One cannot even shake any fluid out, short of a centrifugal spin. Seems like a great cart filler material. Unlike pipe screens, it tightly conforms to the shape of the bridge, it wicks like gangbusters, and completely frees us from the fumes of melting filler. Clearly it ain't gonna burn, no matter what, and that means a lot to me.
So, in the end, the Mega Cartomizers don't impress me, but I'm sure going to pick up a spare Mega Cylinder Atomizer or two, more empty carts, and some 000 Brass Wool.
Out of context that sounds bad, huh? 
