well the US M3s arent that slow, but still slower than the euro ones.
the torque is quite similar, but the euro ones will pull till 8000rpms
the lucky canadians got the M3 GT - 286hp...think it was in 1994-95 and mostly came in green. (i could be wrong)
the reason why the euro M3s didnt come in is because of the STUPID US customs/EPA/DOT.
Same reason we didnt get the E30 M3 Sports evo, skylines, old mitsu evos etc.