From the UOA's I have seen. OE/XL Does as well if not better than pretty much all store bought synthetics. They normally have less wear numbers and more TBN to spare. There are some exceptions to this rule, However for as cheap you can get OE for Its hard to find reasons not to use it for a DD, Or a lightly modded vehicle. They do still have some hydrocracked properties though, But they are Robust oils don't let the OE/XL label fool you.
Good response.
OE = 100% group III hydrocracked
XL = group III/group IV PAO blend
I've never seen any data that the XL line has a group 4 blend?!
Amsoil openly admits it's group III with a booster of group IV to assist with drain interval increases.