I stopped in Muang Khua for two nights, and I didn't regret it. This town is much more than a stop. And then, it would speed up the slow rhythm of this place if you hurried to leave.
If your legs will allow it, I strongly recommend that you go up to the summit of one of the neighbouring mountains, the view point of the town and the Nam Ou are splendid. Take the time to wander along the banks of the river which could lead you to having a game of football, a swim, or a nice chat!
And due its position, on the route to Vietnam, Muang Khua is a good opportunity for travellers who are planning to continue their route toward the East to get good maps and contacts so that they can get to Vietnam calmly.