Well its a long story, but will try to condense it.
Number 1
Okay, started off using cartomisers, pretty soon got sick of that as a 40 Marlborough a day man.
Got hold of a Nautilus, forget coil, think it was 1.8 ohms.
Used 12mg most of the time 60/40 vg/pg. Shop bought juice.
Got fed up with that after about a year, to much throat hit...
A year or so a friend was going on holiday, and could not be bothered to fanny about taking it on the plane.
I had tried it in the pub before, and liked it, so she lent it to me with a full tank of juice for the two weeks she would be away.
Bloody loved it, paid through the nose for exactly the same kit !
Same atty, same mod, same battery's.
After a while switched back to my old favourite black cherry juice, but this time at 6mg, 70/30 VG/PG.
Started mixing my own juice.
Worked okay for a time, but then got massive throat hits !!!!
Tried lots of things to get to the bottom of it, in the end it turned out it was 72mg nic from one particular supplier.
I know my current kit can handle 100% VG out of that, as I spent a whole weekend vaping 100% VG, no nic, no flavour, quite interesting actually.
Number 2
Laziness, I have found that I like 70/30 VG/PG, I like strong flavour, so 20% pg concentrate, easiest thing for me then is Aqueous VG 10% DW, 20% PG flavour, and I am there, with not much fannying about.
Okay, nic addition to take into account, but I buy that in VG base.
Number 3
Maybe just luck, my kit can handle 100% vg, but I prefer 70/30.
Nothing is being stressed, on the nautilus I used to go through a coil every 2 weeks or so.
Don't want to count my chickens, but I have only used 2 coils in 6 months running like this.