I would think it would need a bigger power source...perhaps nuclear?

But in return it sounds like could accelerate up to top speed faster...How much faster? I've heard Ion engines put out about as much thrust as a piece of paper pushing down on your hand...If you could multiply that many times over, that would be a huge improvement over the length of a mission.

I'm sure there are trade-offs as the craft would be much more massive, and probably couldn't rely on solar power. But it sounds like it might be an ideal solution for a Kupier science mission.

Hopefully somebody here with more info can chime in.