^^ Above two posters: Similar names much?
I prefer the old system, it makes more sense, and is neater.
Keep the new system as well, call it "Dig trench"? (I can see it being useful sometimes)
If making channels was "too easy" then make it take longer for dwarfs to do, abstract the removal of the ramps.
in a game where time flies by, dwarves take days to drink and sleep for a week, abstracting the construction of channels seems like a better idea.
Time is irrelevant. It's the player actions that matter. If you only need a channel, ramps will do. If you need access to lower levels, ramps will do. But if you want them impassable or smooth, you can afford to invest that extra effort. Just having them impassable from the get-go is a bit too cheap for the benefits such form provides.
It makes sense from the in-game perspective, not the real-life perspective. In RL, you could, of course, tell your subordinates to dig impassable trenches as one order. But for this to have a
gameplay impact, the time to dig out an impassable pit would have to be disproportionately larger compared to the digging of ramps. Like, quintuple.
Oh, and I wouldn't mind unabstraction of mechanics, either.
Levers may require wire (rope or cable) in addition to mechanisms, proportional to the distance being linked. The laying of the cable
can be abstracted, if only for gameplay reasons, but I'm really hoping that someday the forts will make internal sense as well. For example, burrowing enemies could happen upon the control lines of your defence network...