Exactly my thoughts, and gathered by many threads and discussions most are feeling the same way.
The explanations in game menus are very poor, and there doesn't seem to be any enlightenment on the net as to what they mean, and what changing them will affect.
Taking out the small graphical issues and cars getting stuck in pits etc, this is a great game, pushing boundaries in graphics and physics, dynamic weather and time of day. It makes other racing games take notice.