EFI or CIS, it is all good depending on your point of reference. Me I find CIS interesting and vintage.
I guess one could put an ITB EFI system with distributorless ignition on a 73 RS and it might run better, get more MPG, make more HP, and be more drivable.
However, it just would not be as much fun and a lot of what makes it an RS would be lost!
EFI is probably better in most cases but I love CIS!