joany WiFi was the hard part so far. I switched away from NetBSD for Void for a while before moving to Alpine because I couldn't get WiFi working. Then during my Alpine installation it auto-configured wpa_supplicant for me with a TUI menu. I read the configuration and realized what I'd been doing wrong, checked NetBSD and that config worked fine, so I went back to the good old orange flag. This was over the course of a year or so.
Everything I don't really have working yet I haven't put any time into. Some ACPI stuff works out of the box (brightness keys particularly) but I haven't figured out sleep/hibernation (I keep my laptop plugged in most of the time anyway). Sound, graphics, processor all work fine, as one would expect, though on an old laptop pkgsrc builds usually take a while (particularly Firefox... it took about two days to build it and its dependencies... yeesh).
So I don't have any particular configuration tips for you, but I would expect everything on an X220 to work fine, so if you have any problems asking in this forum should glean you the answer. I'm really enjoying my installation though I'm spending a lot more time playing rogue now.