I'm sure as I type this, it will be answered, but we'll see.
What is better or recommended is all up to you.
PG carries more flavor and
throat hit while VG produces more vapor. In the PTII, yes, any mix will work, really, but if you go 100% VG, since it's thicker, it may wick better if you remove a flavor wick that sits on top of the coil.
Some people have a sensitivity to either PG or VG, so you just have to find what works best for you. Start with a 50/50 mix and go from there. If you want more TH, order higher PG. More vapor, go with more VG.