I feel if the fuel curve on the Demon could be sorted out, it would have made within a few hp of the others...... As they were.
It had the biggest spread in A/F ratio within a pull. Going from memory, it had areas near the bottom where it was in the 14's, and ended up in the 11's at the top.

I'm fairly certain there is 5-10hp left on the table if you could really get one of the annular carb combos dialed right in.

I base that off the last few pulls we made, in which we tried my dyno mule HP950, which was within a couple tq/hp of the others.
I have A/B'd that carb quite a few times against my old CFS built annular 850, and the CFS carb is usually worth 5hp+ over the my 950.
In all fairness though, while the CFS carb does make good power, it also would not have been any better at part throttle than the QFT carbs. It's pretty rich on the bottom.

The dyno mule HP950 is something I built from a bare Holley body and old style HP metering blocks. I used Braswell stepped boosters in it, and it has a tendency to slightly richen up from bottom to top.
Trying this carb on this motor for me was sort of a "control" test, to guage if the characteristic we were seeing of all the carbs richening up was something peculiar to the combo, or just what the carbs were doing.
If anything, on Brads motor, I'd say the dyno 950's tendency to richen up was slightly less than what is typical with it.

Also, I've run that carb on many motors and its never shown a problem being lean before, so again..... As a control item...... If it would have required a bunch of jet put in it, it would point the finger at a combo specific issue, not so much a carb issue.
The A/F ratio was mid/hi-12's for most of the pull, and richened up to low 12's at the end.....with the std jetting I had in it.

The motor itself didn't appear to present any out of the ordinary challenge for fuel delivery to the carbs...... The ones that required really big jets to get the wot A/F ratios right are just configured in a way where that was the case.
My dyno mule 950 was flowing plenty of fuel with only 75/84 jets(primary pv).

The motor was using about 20cfm more air at the top end of the pull with the bigger carbs....... So there is some power to be gained if the metering is really sorted out.