Ive been using a 636L lately seems to work on all the "hot audio" radios i own... and the volume of audio seems to be plenty. Great at cutting out backround noise.. but you have to get up on that sucker.
If you want "IN YOUR FACE" audio..i like the D104M6 older mic. Its dirty ,tinny, picks up a crap load of backround noise.... sort-a- like just yelling into the mic.