For me, nothing is more valuable as a capital than a coloniser, who cares about straight up offense when I can make worlds mine? The ability to colonize is the most powerful ability in the game for me, coz thats the most deciding factor in "will my empire get bigger or not"

^You need to colonize the planet before you can eat it.

But surely you can see how someone else's definition of 'powerful' might be how it fares in a fight?

Yep.  Because I don't have a paid account on the survey site, I can only see the first 100 results.  I closed it because any data beyond the first hundred is useless.

Same, I noticed on a few, mostly on "which is the most powerful..." it was 79 answered, 22 skipped, was a lil odd.