[Nocturnal]

I remote mine (or strip-mine more precisely) extensively since they very quickly bring in huge income with a short start-up time. It's not inconcievable that in less than a year I can get an asteroid belt pumping out over 45K resources from a strip-miner base. But it depends on the economic situation you're in. Do you need the resources now, or can you wait and invest more to get more of them later on?

Also consider the long-term effects: the best value improvement plant improves a planet's value by 3% a year (it can take several years to pay back building one of those, so only build them on larger worlds that focus only on resources, you get a ROI faster.) Remote mining reduces a stellar object's value by 1% a month, over three times as quickly as it would take you to improve it back. So be aware that by remote mining, you really are ruining the potential planet for future generations of Green hippies.

You can't mine from a populated planet. You have to build resource miners on the planet. Also I think the cap of a value improvement plant is less than the cap of asteriods, meaning some might begin slightly more valuable than you can improve them to (not sure about this but I think it was 250% and 300% respectively.)

If you create a planet it will have the same values as the asteriod field did. The atmosphere and type will be random.

So in the long-term, yes, it makes sense to turn most asteroids into planets and colonize them. But you have to consider things like: would it be better for me to have large gains in a resource soon, or spend more time getting this to a rich planet? Is this asteroid belt in a militarily risky position? How long is the game going to go on vs. when will I see a return on my investment?

Personally my expensive high-tech fleets demand minerals and radioactives NOW. And my planets need to devote all their room to research and intelligence. And shuffling around breathers doesn't exactly make me ecstatic. But I do indeed see the point of those who swear off remote mining completely. I'm just a heartless capitalist pig-dog. And if I have a rich asteroid field in a system with built up planets, I usually do build that one into a resource colony.