My feelings are the speakers can be played louder, with less distortion. My experience has been that my MMGs need to be played a certain level to sound best, but start to go over that level too much and things get ugly. The Razor mod has a similar effect as is said when reframing the speakers in wood, pushing that threshold up and cleaning up the sound.
On the subject of reframing the MMGs, whether or not you subscribe to the wood frame's ability to absorb unwanted vibrations (and how much), one fact became apparent when I did mine. The custom frames I built have the same width and depth as a pair of MG12s, but a shorter height. I did this to use a MG12 sock over them, if desired. When inquiring about the "nude" dimensions of the MG12 (who's driver is only slightly larger than the MMGs), I was surprised to find out the depth of that frame is over twice as thick. Made my OEM frames seem quite toyish. The new frames are much more substantial.