I've launched the RMS-29/40-120 motor hardware three times with a G-138T reload. Assembly was very easy - all parts fit like a glove. With the G-138T, the motor is a screamer off the pad. With a small 15 ounce rocket, it was almost too fast to see. Disassembly and cleanup was super easy. Can't wait for the next launch. BTW, if you're using the G-138T reload, be sure to search for on-line assembly instructions. Aerotech has a nice on-line video that includes a step not mentioned in the written instructions that come with the reload. The missing step is to add a wrap of masking tape at the forward end of the grain before application of Super Lube and installation in the RMS-29/40-120.
I will be using them again.