From time to time I think about going back to using Amsoil. I did use some Amsoil products in the past, but I used their XL-7500 or whatever it is called motor oil. I didn't use their full synthetic oil.
It certainly looks from UOAs that Amsoil is very good. Based on what I have seen I would have to say that Amsoil generally looks better then Royal Purple or Redline. But Mobil 1 has pretty good UOAs also and Mobil 1 is available locally.
My guess is that Amsoil is actually somewhat better then Mobil 1. But you can get into all kinds of arguments as to whether the difference is really all that great. And for that matter, Schaeffer's blend is very good and also capable of long drains.
If I did use Amsoil I would not try to go 25,000 or 35,000 miles with it. I think the safe thing to do would be to cut that mileage in half for each oil change.
I kind of think for me the Schaeffer's blend would make more sense. I could still drive a long way, I know it is very good stuff, and I get real nervous once I start getting past 6000 miles on one oil change.
And then too there are conventional motor oils that are plenty good enough in most cars and trucks. Hard to beat Chevron, Pennzoil, and Castrol and 5000-6000 miles oil changes would also be possible with these. Throw in a Auto-RX cleaning every 25,000 miles and you are good to go.
It is really hard to decide.