I tried a PCRC system, and while it worked, it adds lots of clutter to the layout of your r/c car, and more complex startup procedure. It would work good for bashing, but it's too much more stuff to worry about for racing. I stopped using it because it requires warmup time before it goes out of engine start mode, and I didn't like running my car for 3 minutes before hitting the track and not being able to hear the RD during that time. In the end, it was better to just tune the carb. The little regulator valve also puts a pretty good load on your receiver pack.

I don't doubt if an EFI/EFR system came built into an (r/c car) engine from the factory, it would be much easier to use and the added complexity would be neglegable. I am also sure cost would be crazy, and regular carbureted engines would still be competitive in the right hands. The pros/fast guys probably wouldn't make the switch for that reason.

<2 cents bounce across the table>