I would just like to have some opinions as to which makes better encoders and interfaces (particularly each's best models). Is the price of Hagstrom more because it's better?
Depends how you look at it.
Hagstrom sells more to large industrial firms than to the end-user building a MAME cab. Their prices are higher, b/c large firms will pay more. And industrial quality is probably better overall, but it won't make a difference in a MAME cab.
If you're in the U.S. - It's like asking if Snap-On tools are better than Stanley for the shade-tree mechanic b/c they cost more.
Or like asking if BMW's are better than Ford's for your Grandma that drives 10 km a week to the store and back, b/c they cost more.