I've been playing a lot of Forza for the past few months, but when I went back to GT5 the other day I was amazed at how much more realistic GT5 feels as a sim. So now I'm back at playing this game. The only thing that really bugs me is the engine sounds. They sound horrible compared to Forza.
I was able to pull off a pretty good lap time (1:38.457) in a stock E92 M3 (soft sport tires) at Laguna Seca:
Everything in sim, all nannies off.
OEM M3 GTS Splitter/Wing/Harness Bar/Rear Seat Delete, Ohlin R&T, Brembo BBK, Akrapovic GT4, Alekshop Oil Cooler, ESS Tune/Pulley, Recaro SPG, 18" BBS FI, CAE Shifter, Vorschlag Camber Plates, Bimmerworld Toe-Links/End-Links, RD Sport Front Sway, Turner Solid Subframe/Diff Bushings, Awron Gauge.