Did I say i was a doom cube builder? -No.
I was simply defending said doomcube builders... And besides, is there any way to defeat a doom cube? (That is probably why you are worried about them...)
You say this, but it sounds like you're just trying to defend your doomcube building and then backpedaling when you realized people didn't like that.
Anyhow, doomcubes are able to be beaten with a similar mass ship, provided you've got a good pilot and the doomcube pilot is only average. The problem is, with a doomcube at the same mass (or even a bit less) and with pilots skill at the same level, the cube is going to win pretty much every time.
Don't defend doomcube builders. It only encourages them, and we really, really don't want that.
