Yes I believe that 1/2 ml would last longer in the RES than it would in a cartomizer. The reason is exactly what you were thinking. The liquid inside the RES does not fully absorb into the ceramic and therefore does not get stuck like liquid does in the polyfill. It drains down into the atomizer smooth and non obstructed. So in a cartomizer 1/2 ml will be closer to 1/3 ml, where in the RES you get every last drop of that 1/2 ml.
I want to clarify slightly TmeisT post. This is a new technology and no one has used this type of high grade (medical device grade) porous ceramic for a e-cig reservoir before. TmeisT is correct in that the liquid is not absorbed directly by the ceramic. The ceramic is a microporous material. Meaning that it has little tiny pockets (in the order of microns in diameter) throughout the material. Those pores are what store the liquid. That being said, the RES does not function like a "Tank" system. When you inhale on the Alpha the airflow is forced through the porous ceramic, and this displaces the liquid from the pores and drives it into the atomizer.
The ceramic will then seek to be in equilibrium, the pores that had liquid in them, and are emptied when you inhale will draw fluid from the more saturated parts of the ceramic. The RES is always doing this, as you vape, the fluid equilibrium in the ceramic is shifting. This system works extremely well for people who use the PV like an analog, taking 10-15 drags and then coming back to the Alpha 10-20 minutes later and taking another 10-15 drags. This is because the time between use allows the RES to come back into equilibrium completely. Most people will refill the RES before it has been completely drained, because as you get to the lower range of the capacity the distribution of that last remaining liquid is throughout the entire wick (because the ceramic seeks equilibrium), and vapor production will decrease. So the RES is not really built to be run until it is dry, more like until it is almost dry.
This is less noticeable as the RES capacity increases UltraLite RES < Ultra RES < UltraMax RES.
Now I use a 100% VG liquid which is thicker then VG/PG or pure PG juice. This also plays a small role in how rapidly the RES reaches equilibrium, as thicker liquids will take slightly longer then thinner liquids.
The benefit of this system over a tank is that the liquid flow is driven directly by the airflow of your inhale. So if you take a short, hard inhale the liquid is drawn in rapidly. If you take long slow inhale, the liquid is drawn in slowly, it adapts automatically to your style of
vaping. Unlike tank systems which require tuning and adjusting of the air fluid ratio, or work by siphoning fluid from the tank to the atomizer wick. The RES requires NO tuning or adjusting, it just works because of the nature of the design, the airflow generated by your inhale has to go through the ceramic wick before reaching the atomizer, this puts the liquid directly in the flow path, right where it should be IMHO.
The RES also does not leak as the liquid is held in the ceramic. The ceramic is also completely inert and imparts no flavor to the liquid, and will never wear out. Add to that the fact that it is really simply to fill (if you can direct drip you can fill the RES, it is that simple) , and easy to clean it is a really good system.
This is probably an overly long reply, but this is a entirely new approach to an integrated
eliquid reservoir.
You can check out the About Alpha section on the innovapor website, there is a RES specific section including a tab that says "RES in Action" showing in images how the RES functions. Link:
About Alpha Electronic Cigarette: Your source for the best electronic cigarettes in the world.
Cheers!