I liked the leveling system in Oblivion, and hate the leveling of Skyrim. I realize that is a little out of the context of this thread.
That said, I would like the Smithing skills if they were better developed.
1) The ore veins do not respawn, at least in my game. Never, not ever, even after long months spent waiting. In earlier Elder Scrolls games, alchemy was a viable skill to invest in because you could make good money from it as a trade. But if smithing has sorely limited supplies, then there is no advantage to gaining the skill.4
2) The perk tree only allows you to make the equivilent of vanilla weapons and armor. You should, as a master craftsman, be able to make superior weapons and armor if you level the skills all the way up. In some games (Kingdoms of Amalur) you are able to do just that. I level up blacksmithing in that game because that is where you get the best stuff. But in Skyrim, anything you get out of an unattended chest or off of a dead villian is just as good as what you can make. I know that you can make advanced items like Legendary, but that doesn't come until very late in the game, unless you do not intend to actually develop the skills to use the weapons and armor that you are cranking out.
3) the special forges. Everyone in the game hypes that Graymane can make the best stuff at the forge by the companions building. But he makes vanilla items. Nothing special about what is made there.
I would enjoy smithing but the skill is not worth squandering my perk points.