On a 500 hp 408 Chrysler...... Hot Rod saw a 3 hp difference (loss). 500 versus 503 at the crank. Overall the change was an average loss of just over a single foot-pound and just under 2 hp. But with notable gains in the mid-range. I Excelled the dyno report to get those numbers. I also found the average percentage change was roughly -0.3%. WAY within any margin of testing error used in the industry. I'd say it was a wash. But it probably starts better and runs better and cleaner with the EFI. At this small variance I'd say it boils down to personal preference.
Personally I would not fret losing 3 hp at 5800 rpm and I would welcome the 10-15 ft-lb gains at 3500-4000 rpm. I would use those lower rpm gains much more often than the top end gain. In a racing situation the differences would be erased by driver ability and car setup and weather factors and a host of other variables.
Do you want to tinker with jetting or do you want to turn the key and drive? Are you racing at a highly competitive level? or just for fun? Those are rhetorical, BTW.
I'd also be interested in actual first hand results from the Ford world.