Dieselgek,
I would think that with either an electronic or constant flow fuel injection monitoring fuel pressure would be extremely important, as fuel pressure is what makes them both work.
Rex
I've never monitored fuel pressure electronically - never felt it to be important.
We put a gauge on the rails to see if it's working when we warm the engine or fire it in the pits - that's about it. Regulators don't fail often enough for it to be on top of my list of things to watch. I monitor Air:Fuel so I know if there's a mixture problem, and my EMS is still commanding the amount of fuel I expect, then there is a pressure or supply problem. That way, I just saved the car owner money because running the pressure sensor wasn't necessary.
Keeping it simple is something a lot of racers (and keyboard theorists) overlook - by a lot. Look at the Spectre guys - they went just about as fast as the 411 car, on a fraction of the technology, time, and expertise - just by winging it. I think that says a lot about the value (or lack thereof) of over-thinking the approach. Like I said earlier, too many people are out there with 10 and 15 thousand dollar logging systems and aren't getting any more useful info than the guy who bought the Sportsman Logger from Racepak... but, that's just my way of approaching it. Other methods work too, I'm sure.
I just like getting good bang for the buck. There's not enough money for most of the guys in this sport to be wasting it on fancy stuff. All my opinion of course!