I don't know; not saying Miner/Prospector is wrong, because it's clearly a plausible choice, and one I'll probably try in my second save, whenever I play one. But most of the benefits of it are easily available for purchase if necessary, so to me Miner/Prospector reduces down to +1 ore per iridium node. If I want more copper - and I might, since the keg program could use a few more tappers - I can buy it from Clint relatively cheaply. I already have more iron and gold than I have a use for without Miner, and turning wood into coal is adequate (I'm not going heavily into preserves jars or beehives). Plus I don't actually have Mining 10 yet anyway.
Whereas there is no way to buy gems (I think), and only very limited ability to buy geodes, so the Geologist/Excavator perks offer benefits that can't be replicated by other means.
The +1 ore per iridium node is meaningful, but the question is then where one should expect to get the bulk of one's iridium from? Ore nodes, monster drops, Statue of Perfection, other sources? From what I've seen in SC runs so far, the answer is unlikely to be ore nodes. I've gained 12 iridium ore total, of which 4 came from nodes (plus a prismatic shard!
Super-excited about that last iridium node!). The rest came from purple slimes and breakables (boxes/barrels). So with Miner I'd be at 15 total ore but my stockpile of staircases and spicy eels would be a little smaller.
So in the short run I'd probably be better off if I'd gone Miner. On the other hand, I don't particularly enjoy SC and in the long run I expect to get the vast majority of my iridium from the Statue of Perfection (if only one could trigger the evaluation early - I'm at 15 points in mid-summer Y2...).
Even after working through the details like this the choice still looks to me like six of one, half a dozen of the other. Which is nice! I prefer two reasonable options to just one obvious no-brainer.
Based on some other recent discussions, I think this depends on play style.
