Tim,
My abutment is placed pretty far back on my head as that was the only place I had "good" bone. It's a little bit above the top of my ear. The only problem this has caused for me is that with the Divino, the microphones are angled more towards the back so I miss out on some sound coming from directly in front of me, which is usually where conversation is coming from.
I was able to try out the upgraded version (not even sure what model we're on now - they're coming out so fast lately) and it seems the microphones on the upgrade are better at picking up the sounds overall, so some day when I get the upgraded version I don't think it will be an issue.
If you can, talk to an audiologist about it and see what he or she feels about it. I didn't realize when I had the abutment placed that the location would really impact the function of the processor. It was my audiologist that told me I wasn't going to get the full benefit because it was so far back. Even so, I'm still glad I got it. Even without getting 100% out of it, I'm happy with it.
I had my abutment placed under general anesthesia. I could have had local, but I'm a big chicken and didn't want to know what was going on. I felt fine afterwards - took it easy that night and then was back to my normal routine the next day. I never did have any pain from it.
Lori