You still need to accelerate and decelerate and you need to alter the course of this object to match your course. But you get all the resources for almost free.

You still need to accelerate and decelerate and you need to alter the course of this object to match your course. But you get all the resources for almost free. How would this compare to a raft of asteroids you select in your home system to have the exact stuff you need and the accelerate it? I realize there's differences in mass here but I am asking is it material given the scope? Because you are kind of guessing what is going on with that rogue planetoid but the asteroids you could select at your leisure and also hollow out easily while you are in your home system with access to orbital factories, etc. Anyway, fun thought experiment! I totally agree that you would have to approach this as if this is your new home and you MIGHT get to a planetary system you could also colonize at some point. Generations in that idea might seem as foreign as living on a colony flotilla.