Yes it's not 802.11r transitions, I'm too lazy to set that up. I've heard the term "roaming" used in both reference to that standard and in terms of moving between WAPs with the same SSID+psk.
The problem with my current setup is that its never thinking about finding a closer hotspot, it just follows the one weakening across the house until it resets (how I dont know - seems like the phone is doing it not the wifi).
I believe this behaviour is up to the client, unless the WAPs force their hand by forcing a disconnect (or something similar).
My wireless config in OpenWRT has some options that might (?) be useful here: "force disconnect on low ACK" and some distance-tuning variables like max distance to clients (I need to read into this one, maybe it forces disconnects once you are out of range?). There has probably been some thought put into this, I have not read deeply into it.
Some people refuse to use the same SSID for both their 2.4GHz and 5GHz access points because many devices are too stupid to select between them well (keep in mind both the 2.4Ghz and 5GHz networks are broadcast by the same physical WAP). I don't bother, things work OK for me on that front.