Why not an arachnoid form factor with wheels too? Like the tachikomas[0] from Ghost in the Shell world. It usually drives with its wheels but when needed it can use its legs like a spider/insect would. Much more efficient and versatile (and stable) than bipedal form factor IMHO.

[0] https://ghostintheshell.fandom.com/wiki/Tachikoma

I wonder if we're missing the much simpler thought of "Heelys for robots?" Put wheels in the feet so it can move with a quickness, but also let them step around when they need to maneuver into our spaces.