Well, here's a couple more random thoughts related to mining (but not necessarily each other).
Sats may be mineral cost effective, but they aren't
planet cost effective. You only get the benefit of one satellite (that's one UNIT, not one group), and the planet still goes down 1% each year. It doesn't cost you much in current resources, but it probably is bad if you plan on colonizing that planet later and building resource facilities on it.
I'm just guessing, but I think RM is more viable under finite minerals. Then it will probably work like Stars! did, where your planetary decrease is based on the number of miner components working on the planet each turn. I'll look into this later, if someone else hasn't already.
I might, MIGHT, (ok,
I probably wouldn't, but someone else might), use RM if I was short on radioactives or organics and had a massive surplus of minerals. If you're in a bad shape that way though, you'd better start researching to get those resource converters...
One positive to RM is that you don't need a SP in the system - you can sneak around and ruin someone else's future planets instead of yours, heh. In my case, every planet is my future planet, so that isn't as appealing. Muhahahahahahah.
Generally I just find that I have enough stuff to worry about without messing around with RM. If you take a resource penalty, have low maintenance or don't need minerals specifically, or are in big trouble as far as colonizable planets go, maybe you can give RM a shot and have it work out for you. Otherwise, take a pass and work on building better ships so you can steal someone else's planets if you need more resources.
-Drake