There's a serious misconception that carburetors are somehow perfect right out of the box. If I remember correctly, Quadrajet made over 24,000 different models precisely because a carb needs to be tuned in correctly, too. Just because most builders drop one on a motor and it fires up is no guarantee the jets are optimal, the pumps squirt just enough fuel, the secondaries open correctly at the proper time, or that the idle was even set with a vacuum gauge per the manufacturer's requirements. It's something the average guy never does.
And, it's no different for EFI. What you're reading about this system or that not being optimal is a mechanically inclined carb guy on a dyno trying to scope out a EFI program he's likely never seen. Doesn't even understand what the parameters are, how to set things up. The owner's no help, he's only seen it for a few weeks, too. I have yet to read where they called the manufacturer and cleared up a question, either - carb or EFI. That would be admitting weakness, and guys don't ever do that.
Strangely enough, when I talk to car owners who are 1) younger than 35, 2) modify foreign makes, I don't hear "Carbs are better, EFI is junk." They make the systems work better. Same on the Jeep forums, and most 4WD, too. Diesel especially. They are all about the EFI and how to tweak it. And they get results.
I look at engines where EFI was applied, and see gains of 30 hp and 4-5 mpg. That was on a simple engine like the 300 Ford six. Or, this:
Edelbrock Pro-Flo XT EFI Install- Hot Rod Magazine
I get a lot of older guys in at the parts counter where the bulk of the complaints come from. I have to add, if I suggest what website they might get more information about it, I get a deer in the headlights look, too. Mention speed density vs mass air flow, and their eyes glaze over. Yet, one or the other is what they parked out front.
It's what NASCAR will use in the near future. We're turning the corner, carbs are going the way of 6 volt batteries, big blocks, and bias ply tires. We don't use those any more, either. Nobody complains about what replaced them.