... for the last 3 years and even with the higher fees the American funds have virtually returned the same amount as my VTSAX.
A better comparison would be two growth funds, like AGTHX vs VUG (Vanguard Growth ETF). According to morningstar's website:
AGTHX's performance was +16.75% (3yr) and 12.86% (10yr)
VUG's performance was +16.32% (3yr) and 14.04% (10yr)
Actually, it looks like the 3 year performance is the only time period where AGTHX beat VUG. Take a look at morningstar.com's data for those two funds to see for yourself.
Because of some tech stocks, growth has done quite well. You can peek at Vanguard Technology (VGT) performance of +25.48% (3yr) and 17.74% (10yr). Right now VUG allocates 32% to tech, while AGTHX allocates 27%. So if tech continues doing well, VUG could outpace AGTHX (as it has done for the past year).