I've noticed that mines only give +1 production now while I remember it being +2 in Civ 4. There might've been a later tech that would bump it to +3, though I'm not sure on that one. I don't recall any technology or anything that would bump it up from +1, either.
Lumber mill, on the other hand, is the same +1 to production, going to +2 with a later tech. I'm actually building lumber mills on forests and then building trading posts on non-river hills (river hills still get a mine) to take advantage of golden ages. If I discover a strategic resource later on, that's only when I replace the trading post with a mine.
Lumber mill, on the other hand, is the same +1 to production, going to +2 with a later tech. I'm actually building lumber mills on forests and then building trading posts on non-river hills (river hills still get a mine) to take advantage of golden ages. If I discover a strategic resource later on, that's only when I replace the trading post with a mine.