I have been co-sleeping with DS on and off since his birth, but with all these studies, I'm confused. I BF and he's up quite a bit at night, so it's just easier for me. I don't use pillows, our mattress is firm and I don't have a duvet, just a large cellular blanket.
it'll be safer with an 11month old than it would be with a newborn. If you've been doing it from birth then I wouldn't worry about it now. Imo the advice not to is directed at the inebriated! Ds (6months) ends up in our bed at 2am every night and we do have a duvet and pillows, which I keep well away from him, but just saying that I think you can relax a bit.