More PG=thinner, less vapor production
More VG=Thicker, more vapor production
Although you can also attribute flavor properties and throat hit "oopmh" to more or less of one or the other, you can also change the throat hit from nic levels, and you can change flavor by adding more or less.
I personally don't like anything higher than 50% PG. From that point, I dont care what the liquid ratio is. Even I vape almost exclusively on subohm built RDAs, I goal is not clouds. Im after that dense, moist lung fill. And Ive got plenty of 50-50% liquids which can do just that. Ive also got plenty of Max VG liquids which can do that.
For me, throat hit mostly comes from nicotine content and the heat of the vapor. If you vape liquids very high in PG, like 70-80-90%, you'll get throat hit from the PG as well, but its not the same kind of throat hit as what the nicotine provides. For me, its an irritating, sharp, unpleasant smack in the throat that makes me want to cough, as opposed to smooth, deep, satisfying throat note. Thats what I call it.. a throat note.
Also.. PG is often said to carry flavor better. IT does.... BUT, DO NOT automatically attribute that to liquids made up of more PG having more flavourful vapor. If that was the logic, 80%VG liquids would be bland and dull, yet Ive got plenty of mostly VG liquids which are powerfully flavourful.
End of the day, what it comes down to, the liquid ratio SHOULD BE DETERMINED by the mixer. Everything about how the liquid is made will affect how it tastes and feels. If you have a recipe for an amazing liquid which is 6mg and 50-50, and you want to make that same liquid at 18mg and 70/30, you cant simply just add more nice and change the ratio... you need to work up an entirely different formula.. and its very possible you will never replicate the exact flavor at two different ratios and nic levels.
(This is part of the reason I generally turn my nose up at such liquid vendors who allow you to so called, "customize" your liquid, by telling them exactly how much Vg, Pg, Distilled H20, Nicotine, and Flavor shots the liquid should contain. How in the hell could they put out a consistent "banana bread" to every customer, if every customer wants an entirely different liquid? Its a rhetorical question.)