I run Mobil 1 synthetic throughout my Runner.
I used to run Amsoil, but it was a pain in the butt to have to order or track down dealer. With Mobil 1, everyone carries that, so......
As far as change intervals I go with 6000 miles, like jx said, its nice changing oil 2-3 times a year versus 5-6 times with regular oil.
I also switched the wifes 02' Civic to synthetic after her free dealer changes ran out.
Synthetic just gives my a better piece of mind , and is the only thing that will go in my vehicles.
I say go for it.