For my thirty v-verts, it's been 'bout 70% long term success rate. I think a large factor in that percentage is that I was available to aid them when they had issues and/or questions.
You are so right, it is nice when you have either this forum or someone who is experienced enough to know the pitfalls and help them get through the disappointments in things like equipment failures or even things like possible sensitivity to PG. I was lucky, I started with Blu, which is all VG. When I tried PG/VG juices, I quickly found out I was horribly sensitive to them. Another friend I know bought an ego over a year ago and tried it but put it away in a drawer for a year because it hurt her throat too much -- it was the PG sensitivity, which when she mentioned it, several vaping folks at work suspected right away. She went to VG and is doing really well.
I know if I had started with PG, there is no way I would have been happy with it and really not sure if I would have been willing to even try 100% VG juice. PG was THAT bad for me. I darn near had to go to the doctor over it.