My good ear is profound, and has been for maybe 2 1/2-3 years, but I still get enough speech to understand 30-40% of what's said. My left, my bad one is profound to response and had been for probably more like 8ish years. It went totally unaided for 6 years, the Audi I had when I need to get powerful aids didn't recommend I get one for that ear, that I wouldn't get much speech and the vibrations from the sound waves hitting that ear drum would make me dizzy. When I got my next more powerful has last summer I got one for it, but I don't use it much, I don't get speech out of it and it does tickle inside my head. It's just noise and it's distracting. Anyway, since it's been without sound for close to a decade I'm afraid the nerve on that side might not have been stimulated enough and I wouldn't get results as good as the other side.
Personally I'd rather do the worse side since I do mostly manage with my better, I can't call it good that's so silly, but if I am going to do this I'd like to stack the deck in my favor. Long story short they're both bad, one is just slightly better than the other, and one's been without sound for a long time, it could end up like someone that's been deaf all their life and getting implanting as an adult. If I did the worse ear it could up not worth it 
