You are welcome Captain Dan!
Just to clarify, I meant that with it set at 4.8v, you will probably notice a drop in performance quite quickly - like within the first 30-60 mins of vaping. You might get around 2 hrs total vaping time if you are lucky. This is my estimate, and of course your experience might be a lot different. I do know the stick batteries like the X-fire work better with higher resistances. I have a 1300mAh spinner I first started with and could almost get a full day vaping around 2.0 - 2.4ohms and about 3mls of e-liquid in an Evod clearo. If I put a subtank on it, I might be lucky to get an hour or two total.
As for the pipe you linked above, (I think it runs on an 18350 not 18650 by the way) you are going to have a similar issue there. This is an unregulated device so it delivers the power the battery produces with no regulation up or down like the x-fire has.
So it will start off giving out 4.2volts which will only be around 14 watts with the 1.2ohm heads - you'll find that is probably not enough to run the subtank satisfactorily. Actually, with the pipe you can use the 0.5ohm heads and have a better experience (these heads won't work with the x-fire though) - you'll be producing around 35 watts with a fresh battery. But then you need to consider the amp load on the battery. You'll be pulling 8.4 amps and many 18350 batteries are not rated for this load. If you go down the pipe path, you really need to buy good quality IMR batteries (AW batteries are a great bet if you can find them in the UK from a reputable supplier) and remember that if you have a short the only protection you will have will be your own vigilance an experience.
Main thing with the pipe is you can't control the vape. As the battery runs down, you'll get a weaker and weaker vape. Remember the 18350 batteries are only 700-800 mAh as well so you will only be getting the full power of the battery for a short time before the performance drops off significantly.
Both devices might be better suited to something like an Nautilus or a Kanger protank of some description.
Sorry for the ramble, but I'm trying to cover all the bases for you. If you are going the subtank route you will have better results with something with a higher mAh and something that is regulated up to at least 15-20 watts - 30 might even be better. What about something like an MVP3 from Innokin or the new subox from Kanger?
