...Have you actually tried to fly the Excelsior yourself, or are you judging it based on watching HELMUT's videos?
I ask, because I have tried flying it myself, and I find that it's just not worth it; the ship is incredibly unforgiving of even small mistakes, and accomplishing things like HELMUT's solo battlestation kills requires many, many attempts - and that's once you've gotten skilled enough to even give it a serious go.
So that's my advice: if you think the Excelsior is implausibly overpowered, give it a try. Personally, I'd rather be flying just about any other premium-quality ship: Tempest. Hyperion. Aurora. All of them are better for me than the unwieldy Excelsior.