cool, love this. basically GT5 is a nordschliefe sim for me.
Adenauer Forst is tough for me too. i'm not consistent about it, but i'm much better now than before. the key for me is clipping the kerb at the 2nd apex on the left hand slow turn before the last turn and exit. if i can touch the kerb just right there and maintain my speed between 65-70mph then i'm doing alright. the biggest lesson i learned here is to be patient on the throttle coming out of that turn. on and quickly off a bit so you don't understeer through the last turn & exit.
for some reason, once i clicked with Bergwerk, i haven't had any real problem with this one. the lesson for me was to brake early a bit before you enter, and then brake lightly twice to maintain the line. so, three brake taps do it for me. if you don't maintain the line you'll be on negative camber and lose it.
Schwalbenschwanz... yes i am not consistent here either. the entry is the key. this is one section where it seems you can't be too ambitious with absolute speed but must maintain an average. if my entry is slightly too fast i'll be struggling and messy all the way through Kleines Karussell.
now i'm just trying to find my max speed, grip, and braking needs at Galgenkopf. not so hard, just don't know my limits yet.
Aremberg.. this is my current project. it's not 'hard' per se, but getting entry speed and downforce coordinated is tough at the limit... gotta know the car really well. in high speed cars it seems i'm able to hold it together at 185mph here before hard braking. maintaining the balance & line into the slow apex is testing my timing right now.
simple as it is, if i'm not really focused then Eiskurve gets me due to the off camber bit just before heading uphill.