If they're proper BMW and are as good as the ones for the 1100 then I'd say they're OK. Mine saved the head from getting scratched when I dropped it and it's still in one piece.
Doddle to fit, look OK, haven't crash-tested them (yet!) although I dropped my 1150GS (offroad) a couple of times with similar protectors on and they did the job.
The hard nylon BMW cyclinder head protectors are okay if the bike simply falls onto its side. I dropped my bike at slow speed and the plastic sheared from the metal where bolted to the cylinder head. The protector did its job but was scrap afterwards.
Try the Touratech alloy protectors from the GS range. Built for off-roading and far more robust and able to take knocks.