I had an SE W850i for a year and loved it. Last month looking at an upgrade. Like many I looked at iPhone, N95 8GB and considered waiting for a W960. In the end I went for the N81 8GB.
This has exceeded most of my expectations, which were high! The sound quality with my replaced headphones is excellent from the music player. I don't use the nav wheel so the criticism people point towards does not affect me. The menu system after SE phones took a little getting used to but ok now. Call quality, movies etc on this phone are all fine. People have criticised the build quality. But its ok IMO.
I recommend the N81.