I hate joining band wagons but I've been playing DF since it became a thing on the SA forums, way back when now (probably, I can't remember version numbers from when I started).
I bought the Steam version because take my money! Tarn earned it with a game like this. Then went back to Classic because I couldn't handle being kicked to the mouse..I played a lot on a laptop so didn't even have a real mouse, and it made it more accessible. It's a tiny game that can suck you in and kill days on end.
Now, I downloaded v50 because I missed playing and wanted to get back to the old school DF, with all the key-highlighted menus.. and you can't even USE that style menu? Unfortunately this thread has answered my question for "how do I get the old sidebar back or display the key bindings on the icons..." -- download v47 again. I really hope I'm not a minority on that, because I liked the old UI - not necessarily for speed or anything but because highlighted key bindings was what made it easy to get good.
It's not unplayable, but it definitely killed a lot of the enjoyment I had for the game for what I thought was an excellent UI for something so complicated. I'm used to text-based interfaces and felt it was a good one, especially with the key highlighting the way it was -- yeah, it takes some learning and practice, but I could also just look right and find the binding - always, and everywhere.