[Dracus]

I capture planets intact and force ship the aliens off to camps. It is my play style to role play. In time I will move them to planets that they can max out on.

But to answer your question. I can quickly capture and ship aliens to useable planets with a lot less cost then to convert the planet to fit my race. So the plus is that if you are say oxygen/rock and you capture a none/ice race. You can max out all the none/ice planets in your systems.