Good post. I just came back from NHMS in New Hampshire - my E90 can make it through almost the full day, with no pad fade, on Pagid RS-19 front and RS-7 in the rear. The last few laps of the last session, I was managing my brakes a little. I have stock rotors and I track-bed the pads (run stock pads on the street). I get zero pulsing through the wheel, even after swapping back and forth w/pads three times now.
The tip (VictorH and 4 Sevens) about driving for a few days w/the race pads to scrape-off the bedded material when the brakes are out of their operating temp? Spot-on.
To my mind, if this car had brake ducts...problem solved. The brakes have enough mass and great leverage w/the large factory rotors. Would love fixed calipers of a BBK for quick pad changes, but I'll deal with it.
I used Cool Carbons for my first track day and I had pad fade by the second lap session, even after a very careful bedding process. Once I upgraded to Pagids, problem solved. I'm going to look into the ducts as this is the real issue here. I'd save your money for now, although a BBK would be a nice upgrade for lower cost comsumables in the long run and pad changes at the track in 30 mins.