The weak setting is much more realistic, the strong is the same as it was pre 2.0
I have been racing online with the weak setting and it's now only possible to pass someone using slipstream on a huge straight and it takes a long time. No longer can you follow a faster car around the track by staying behind it.
I had an online race today with some GTP regulars, me in a 07 WRX and they had Evo 6's and the like and I was able to easily pull away as my car was faster. Pre 2.0 they would have kept passing me on the straights and I would keep having to re-pass them causing a yoyo effect which is very irritating and unrealistic.