PG is thin, lets
through the most flavor, the most TH but also the most of nicotine's skin irritation
VG is thick, dulls everything PG lets
through, but adds thicker more persistent vapor
18mg nic in 100% PG (what I started with) made my tongue sore and numb. So I tried 70pg/30vg which it's the blend Backwoods Brew uses. 70pg/30vg was my favorite blend but I think with cartomizers 20% or less VG keeps my cartos working well longer so I am currently buying 80pg/20vg when I can. I can thin 70pg/30vg a bit to use in cartos too (bit of distilled water works)
BTW I like Vixen's Peach