Hi Poriolo,
I am an Osia wearer and I love it. I'm not sure what the down sides are. I don't experience pain or discomfort at the implant site, the magnetic attachment is comfortable, and the sound quality is great--it's truly like natural sound/hearing.

I guess the negatives could be 1) that I have a lump on my head where the implant is, 2) when I lay in bed to watch tv I have to take my Osia off to avoid it being pushed into the pillow and creating feedback [I bought a bluetooth neck speaker that allows me to hear the tv just fine], 3) not knowing when the battery might go out [batteries usually last about two days, so I try to keep up with it and I go ahead and change out my battery if I'm going to a meeting or somewhere else where changing the battery might be awkward], and 4) not being certain about how and when the device gets replaced or the costs involved with upgrading or replacing the device. I wish the companies would be more transparent with this type of information. I also wish the market would bust wide open so prices could go down. It would be really nice to have replacement devices be so affordable that you could purchase a spare to have at home in case something happens to your current device.

I hope this helps. If you have any questions, please ask.
Stephanie