Lads, Rick wasn't saying that EFI systems are crap. He was saying that the uneven air/fuel distribution with a 5th injectors system is bollocks.

If all the cylinders were inducting at the same time, uneven distribution would be true. As the cylinders induct at different times, the distibution is a lot more even. The plenum acts as a pressurised storage facility for the air (and the air/fuel if the 5th is used) and just fills the cylinder that has an open valve.

Do you mean map on the ECU chip or map sensor inside the ECU? 2 different things?

The issue with your agruement is that the 5th is there to add the additional fuel that the MFI system cannot add. When the ECU throws in it's on boost fueling and it still runs lean, it can't compensate so the 5th injector is then mapped to supply the additional fuel. If it's done properly, there will be no damage to the engine. But like ANY system, if the set up is out, it will either run badly at best or damage your engine at worst.

Manufacturers don't use 5th injectors for the same reason they don't use carbs anymore. Or single point injection. Technological pregression and advancements which are also coming down in price. It took the motoring world nearly 100 years to move away from carbs. Then there was MFI, then multipoint (batched and sequential fired) and single point injection.

The 5th injector is not as bad as people think they are or make them out to be. They do a job and do it very very well. However in my opinion, you cannot beat a properly set up, decent quality EFI system.