Here's my thoughts on the limitations of the system that I posted a couple years ago:
https://www.rctech.net/forum/showpos...postcount=2915

No, the system will not be compatible with any other radio brand on the market and there are no aftermarket Rx's that are compatible with RP, it's now a relic from a company that went out of business because they produced a series of 1 and done products without making any improvements to their designs, marginally acceptable radios and fundamental design flaws in their servos which were prone to stripping gears far too easily. They are no longer in business for a reason

It is true that they were the industry leader when they first came out, offering features nobody else offered but they faded away within 5-6 years.

One of the coolest features they had with their servos was a retractable enclosure in the servo case to stuff the excess servo wiring into the servo without having to trim the wire, I really wish more servo brands would do this!

There are still a couple local racers in my area that still run RP with success, the radio definitely stands the test of time provided you can put up with its quirks.