I had an e46m3
OE Trim: 3475 (no fuel, no driver)
I removed the rear seats, rear trunkliner, added GC Coilovers ($1500), added a Titanium Muffler ($1200), had lighter wheels + tires ($2500), front BBK ($2500) and was down to 3200 lbs. (no fuel, no driver) @ $7700+
I HAVE and e90m3
OE trim: 3630 lbs. (no fuel no driver)
I removed the rear seats, removed trunkliner, installed f/r BBK ($7500), installed a lighter muffler and X-Pipe ($2000), installed a Spring Coilover Kit ($1000), and lighter wheels + tires ($2500) and am down to 3400 lbs. (no fuel, no driver) @ $13k
This is e90/e92M3 vs 1M ...and the 1M IS a lighter car and you can "easily" remove 200+lbs.
It will be more nimble and change direction better at the track then an e92/e90m3.
I've worked with 2 teams running e82 chassis for racing, so I can tell you this chassis is capable at the track.... more then an e90/e92m3 = faster for less money.
There are a TON of better candidates for race cars then both these platforms.
But speaking strictly 1M vs. M3 = the 1M WILL be a better/faster for cheaper track car then the e90/e92m3. Period.
As far as street comfort and dd capability = e90/e92m3 hands down.