There are some good answers both of these questions in the ask the vets and health sections.
There's even a pros/cons on pg/vg
Most liquids are a combination of PG and VG.
Generally, it's said that PG gives better throat hit and flavor and VG gives better vapor...
VG is also preferred by those allergic to PG.
It's a matter of preference. I prefer a VG dominant liquid.
I get heartburn from too much PG.
Why don't you get a PG dominant AND a VG dominant liquid and see for yourself.
Alien Visions makes awesome VG liquid.
There's awesome PG based liquid everywhere.
Good choice on a 510 ;-)
Where are you getting your liquid from?
I'd say get it from 3-4 different places.
Start here or look for advice in the
reviews etc...
I like these folks. Good to deal with.
no shortage of excellent suppliers.
Backwoods Brew (in suppliers forum).
Alien Visions VG
nHaler
VapeRite
Vaporbomb for some nice sweets
Vapor Station
Halo
happy smokes
iVape
Freedomsmokesusa
good dekang from Madapes and StrictlyEjuice (inexpensive and good)
also VERY POPULAR: (perhaps the most popular)
Tasty Vapor nice sweets
Ms. T's nice sweets
Check The Suppliers forum for good deals and sales.
Good advice from purevapes...
~also~
I think some flavors come alive better in PG or VG...