It most definitely is smaller. I was wondering if would still allow the gases to expand and 'clean' out the cylinder the same way the standard mod pipe does. I would imagine it does, but I'm dont know a whole lot about expansion chamber geometry and performance. I do think there would be better flow as the outlet isn't on the bottom of the snail part. But again, I'm not sure.
If modifying the bracket and the exhaust is all that needs to be done and it would still perform well, then so be it. Otherwise I'd like some more low end hit and I'll just trade.