There is no challenge in this AT ALL. It's now like: Oh, I can't make it in 5 tries with the stock setup, let's just tune a bit. While with for example the Focus challenge I had to restart at least 40 times to get gold without SRF. That was one hell of a challenge. There's no challenge in this, at least not a challenge I like to see.
In fps's there are levels and difficulties I cannot achieve. So why should GT5 achievable for everyone? WHY?! Why can't some people be satisfied with having silver or bronze, while a lot of people play fps games can be happy not being able to achieve the hardcore extreme level?!
XP should be lower with a big tune anyway and also lower when using aids like in Forza..