Had a non-union some years ago and got a plate inserted to come round to the most insane pain I’ve ever experienced – way past screaming in agony, won’t someone just shoot me type pain. (Don’t let this put you off!)
Had to have to plate out due to it contracting when the temperature dropped and causing a bit of discomfort. This was a much better experience.
Broke same clavical earlier this year and tried to push for an op straight away as I suspected part of the reason it was so painful the first time round was that it had been left for weeks on end (had many second opinions; eventually a physio told me it definately needed repairing). As the xray this time looked hopeful the NHS weren’t up for cutting me open and, thankfully, it’s healed ok on its own.
In short I think it’s definately worth getting the op – bones aren’t meant to float around in bits.
If it ever happens again I’m gonna try these guys out: http://www.physioclinic.net/ apparently the treatments aren’t horrifically expensive (and work?); if it means I don’t have to spend so much time incapacitated as I did earlier this year it’ll be worth paying for.