Get your 2x credits regardless of having a booster. However if you have a booster its 4x(ish)! There is a infested defense on pluto I was doing that takes about 5 min. Just need a Speed Nova, Gmag and a Mesa. It yields 92,000 (with credit booster). Did a T4I, that game me 104k ish. Good stuff, I got modding bills to pay!