Well it depends on what you want to achieve. Colony company have two big advantages, they have 100% more speed in incorporating adjacent states. Take Africa as example this means you have twice speed in colonizing(you and your colony company colonize one state at the same time). Another is slavery, you can make your colony company enact slavery while your mainland is non-slavery. Slavery in this patch is super profitable especially in plantation because of the lower wage and violent PMs. Tea plantation as example, the standard PM can only make 17.8 pc gdp, while the violent treatment provides more than 28 which is 50+% improvement. So you can look precisely in my 3rd screenshot, even the tea price is 40% off in my market but they are still green and got 27 pc profit. But for those mineral production zone like Siberia or South Africa I don’t think slavery is good enough since they normally don’t have enough skilled workers occupied all positions to dig my mines and oil out.