While I generally agree with the "GT'S track creator FUCKING sucks!" sentiment I should confess that I don't mind the Toscana ones, in fact that is by far the best track scenery / style they have (yes it can have some shitty corners but they're usually not terrible or can be tweaked out fairly easily).
That Eifel Circuit one with the "over crest, hello sharp descending corner" sections are just ridiculous though, I expect to see some of those on a Mt. Ahrshole track soon too. And, while I generally don't like the Eifel Kart track courses in general, I should confess again that they at least were used surprisingly well in the earlier rounds (multiple tight S-turn type configurations or something).
But I'm like Chrome insofar as I'm mostly just doing it for the prize cars, I might try a few times to get a halfway decent time according to whomever has times up on my friends list at the time but I haven't gone back just to redo any of them for a faster time.
EDIT: Going through the Academy Prize giveaway on my other account I notice there actually IS a ridiculous Mt. Ahrshole track with stupid corners / elevation, it must have been such a horrifying experience the first time around that I blotted it out of my mind!