Different lock, feel and tons of options . - R&D Precision PW9 Colt/Glock 9mm 5 inch Upper Receiver Kit

Can’t say any negative with this upper from R&D. You have so many options. Did I say wicked looks and features. I have countless conversations with the owner(Randy) and he walked me through the process( went to the C5 lower/mp5 lowers) and went flawless. It cycled well and customer service was just awesome!!! Good luck with R&D this was a great and fun build.
Dennis