Thanks to Arky for the correction.
You're quite right in that 124dB seems a lot, but in confined spaces things can get out of hand pretty bad. I intend to put it in a guitar cabinet with 2x12" 50W speakers.
One purpose of the Shure appears to be the concert piano, so it should also be able to handle the rather more subtle approach as well.
I gravitate towards the Shure as well, allthough it's hard to make a comparison, because there's very little on Youtube on this.
Just for the sake of spelling, in this video, http://www.youtube.com/watch?v=gxTS8...e_gdata_player
it's called a boundry
microphone. I like it.