Agree... LSD is important in stock trim. And remember... IS-F is on smaller tires to boot. The sad fact is 'most' of the improvement... is honestly due to finally moving to Michellin tires... the car has always been as capable... but Bridgestone suck. There is a reason that every car that has claimed top honors... have one thing in common... Michellin Pilots!
CTS-V needed to do it... IS-F needed to do it... BMW has been doing it for sometime now.
I raced my IS-F... as is with no LSD... and still have the times to back it up... BUT I did put on 'D.O.T. Race Tires'... simply because I know the importance tires can make to an overall package.
Again... I love M3's... I typically flip my cars every 6 months... and so I wanted to try something new... I've really taken to the IS-F... and just haven't found a better car, that can do 'everything' so well... M3's are still very very nice cars... and the reason multiple makes sell... is because they fit peoples needs better for some than others.
2010 ZR1 3ZR Wht/Blk 10.7 @ 132
2011 C63 AMG P31 Car Blk/Blk 11.8 @ 117
2010 Nissan GT-R 10.8 @ 129 (Sold)
2008 Lexus IS-F (Sold) 12.5 @ 113 / 2008 Shelby GT500 (Sold) 11.3 @ 126
2008 e90 M3 6MT 12.8 @ 111 (Sold) / 2006 e60 M5 12.4 @ 114 (Sold)