Quoted from karmalord:SM hands down. It is a better pin than IM IMO, in every aspect.
I had both and it seemed that IM got more play time. It is a brutal game that kicks your ass, which in return makes you want to hit the start button again. SM has longer ball times and if you have a long game, you want to step away from it. Both are great games, but IM got more plays just due to the shorter ball times and it just calls you back for another whoopin.