I found a good Read on the 1M from WSJ's Dan Neil here:
http://online.wsj.com/article/SB1000...991133766.html
The write-up is funny and engaging but Dan needs to correct some facts:
1) The BMW 1M and the M3 do not have an electronic limited slip. Only the 135i does. A mechanical limited-slip is far superior and it is the performance driving enthusiasts really want.
2) The 1M is not 77 lbs lighter than the 135i. The BMW Owner's Manual lists the 135i at 3,298 lbs. At 3,362 lbs, the 1M is actually 64 lbs heavier than the 135i.
More details on the write-up here:
http://www.onehotlap.com/2011/10/goo...-dan-neil.html