The furthest I made it was Sweet 16 in Season 18 - besides luck of the draw, I recall having a pretty deep bench back then, and I focused on going as far as I could, so may have put more effort into the games. I even picked up players for my roster as my Cup players.
Now, I just look at them as scrimmages I don't have to go out and find. If I ever did make it down to round of 512 or so again, I might consider going for it.
-oo-