That has little to do with the bird, but with the man flying it. The D-11 offers no advantage at all over its brothers when it comes to bomber busting other than increased perk payout. Same guns, same frame (but less fuel). I, too, have the lowest k/d vs the D-11 out of all 47s, but that's because it's a rare bird more often used by experts than not.
And yes, other planes are much more capable for hunting bombers just by their specs.
the d11 with the right convergence setting is the deadliest bomber interceptor in the game hands down. It's survivability along with its lazer like 50's forces me to put it at my #1 spot.
There is a reason "the best" fly it when they do
I will state that once you get above 20k the game totally changes. Only the Mary, 152, and comet excel at the highest altitudes. Although these runs dominate the game, I promise you the d11 out performs in getting the job done from my experience.
Numbers are diluted by player preference. I am not trying to be "right" just simply speaking from my own experience. I've had over 10,000 engagements in bombers in the past 2 years.That is a variable the statistic do not show.