Guess I've learned quite a bit since I posted. Been vaping mostly NETs, some of which are not real carto friendly. 60 or 70 PG definitely works better as does topping off regularly. I am, however getting a full workday from one carto and luckily haven't burnt one yet!
I did have one carto I messed up. Flooded when filling so was blowing it out into a paper towel. Guess I blew too hard, something popped and ALL of the juice flooded out. PITA mess!