I'm not much of a lap timer guy but I was in a plateau for awhile. Some of that had to do with car issues (E46). For awhile, I would comfortable lap for 20 minutes...never really pushed. I did set some lap time goals and started to push a little harder. Reading Speed Secrets helped tremendously!
Yeah, coming on and off the front straight is bumpy. Not much of an issue since I stay low on the banking. I clear the bumps and the car will settle before I need to get on the brakes. Those that start higher on the banking will face more of a challenge because the bumps are right in the middle of the zone. Not sure why people stay up there, I can gain as much as 3 seconds on a car that starts turning in from high on the banking. Then entering, its just a matter of unwinding the steering wheel a touch under full throttle.
I do not have EDC on my E90 but I think the E90 is ultimately faster on this track vrs my 330. On the front straight, I can get over 150mph in my M3 on the speedo. Can barely touch 140mph on the 330. As you can see, there's only two series of linked turns and a lot of straights. Above 100mph, the M3 is significantly faster.
I think the 330 is better on the other tracks which feature a lot of complexes of turns.
I have the TC Kline S/D (x2 adj) with 600fr/700rr springs on my 330, Dinan Stage 2 w/ GC plates on my M3. My 330 is every bit as compliant as my M3. I think there's a middle ground and my 330 feels better on those transitions. If I had to make a comparison, the 330 feels like a well mannered church girl. The M3 is like a crazy bitch because the back end will come out real quick. But not a slut because you can stay in control her of ass pretty easily.
2015 F34 328iX GT Glacier Silver
2011 E90 M3 Monte Carlo Blue
2004 E46 M3 Imola Red