As a basic response, they scare me. I can understand, but do not appreciate, the motivations behind going through a surgery that does carry risks (even if it is one of the safer surgeries you can have) in pursuit of hearing. And again, if you choose to receive implants as an adult, that's your choice and not my problem.
Childhood implantation, on the other hand, I am against. This isn't something I can really flail either way about- I can't understand remotely how someone could put their child's wellbeing at risk for the sake of giving them access to communication through hearing as opposed to some other sense. I've seen the idea that you are 'making the choice' for your future deaf adult by choosing not to implant them in childhood, where it is vastly more successful- and to be honest, I have nothing I can offer to that. If you choose not to implant your child, you are making a choice to protect them, and every choice has consequences. And your child might just grow up to hate you for it- and you might just regret it.. but I still believe it is the best choice possible.
I'm not going to dispute the effectiveness of implants- the fact that quite a few members here have experienced dramatic increase in speech perception, environmental awareness, so on and so forth, is proof in itself. Implants almost always work.
I am not against teaching children how to speak or speechread- both are quite helpful skills to take out to the world. That said, I think the price paid for oral -only- is a price too great- prices plenty of members here have paid, ranging from being isolated from other deaf children, suffering your education because you aren't using a language that is completely accessible to you, losing out on time that could be spent.. being a child, in speech therapy. Those are very real, very important prices.. and for what? So you can say your child is better than other deaf children?
But again, I am not against speaking or speechreading in any way. I simply think oral only takes away the balance that can be found in other approaches- namely, using ASL as a primary, accessible language, and also being given access to speech- just not so much that it outweighs the rest of your life, or that failure is seen as a failure on your part.
I know that quite a few people here might disagree, but those are my 2c.