MWR is well known in racing circles, but not so much with street riders, as they are not marketed heavily and they are more expensive. My experience with MWR is on my Ducati Monster, which ran a little, but noticeably, more smoothly after switching from K&N to MWR.
They now have two air filter models for the little Yamaha.
One is a 'Race Use' only filter, and requires ECU reflash or fuel management controller:
http://mwrairfilters.us/prodDetail.asp?ID=4115
The other is a 'Performance' filter that can be used as an OEM replacement. ECU reflash or fuel management controller is recommended but not required:
http://mwrairfilters.us/prodDetail.asp?ID=4114
Installed in R3 airbox:
They now have two air filter models for the little Yamaha.
One is a 'Race Use' only filter, and requires ECU reflash or fuel management controller:
http://mwrairfilters.us/prodDetail.asp?ID=4115

The other is a 'Performance' filter that can be used as an OEM replacement. ECU reflash or fuel management controller is recommended but not required:
http://mwrairfilters.us/prodDetail.asp?ID=4114

Installed in R3 airbox:

