The following excerpt is from "Sport Rocketry". The intention is to allow guests to get a basic feeling about a kit. We strongly suggest that you get a copy of the referenced Sport Rocketry and read the entire article. Inside you will find many helpful hints in construction as well as other useful information. For more information, use the two links above.

"More commonly called "micro motors" due to their slim 10.5 millimeter diameter . . ." 
"The small diameter of the Apogee motors allows smaller diameter rockets with less drag for increased altitude performance." 
". . . the motors use black powder propellant (not composite) . . ." 
"The Apogee A2 motors had an average total impulse of 2.31 N-sec, plus-or-minus only 0.01 N-sec - a very tight tolerance." 
"The small nozzle of the Apogee motors makes them difficult to ignite.  I had a 40% misfire rate using the Power Punch igniters supplied with the motors." 
"Late-breaking results from NARAM 38: . . . Most competitors were very frustrated with the motors due to the high misfire rate and the large number of lost tracks." 
"Apogee sells body tubes, centering rings, and nose cones for the 10.5mm motors." 

The entire article gives the impression is that these new motors will have significant effects on competition rocketry, but that there are some reliability issues to work out.