I'm a little over a month of vaping almost exclusively V4L and I think I have a problem with the PG base. Lately when I wake up in the morning, I've needed to cough up a bunch of phlegm before I could vape. Starting this last weekend I thought I was getting sick. Congestion, tightness of my chest, etc. Earlier in the week I increased my water intake to 3 liters of water a day. That really didn't help. Yesterday afternoon, I switched over to pure VG and all of my symptoms have progressively gotten better. I guess my problem was with sensitivity to PG. I plan to stay on the pure VG for a few days to see what happens, but I'm a little disappointed that I can't seem to handle the PG.