Well, I've received my N86 NAM (pre-order from Amazon) several hours ago and I have been comparing it to my N85 NAM. So far, I am not very impressed.
IMO the N85 is a much better looking phone. I have the copper version and always thought it looked pretty good. The Indigo N86 battery cover has a very dingy looking matt finish, as does the keypad surround, not very attractive. The black chrome surround of the top surface is a fingerprint magnet and, also IMO, not very attractive. The selection keys are thin slivers (reminiscent of the miserable keypad on the N82) and are hard to operate with the flat of your finger. The dpad also does not work nearly as well as the one on the N85 and I am finding it very easy to activate the select when trying to only navigate. It also does not have a well defined inner edge which is very useful when trying to use the dpad with you finger nails.
Build quality seems very good.
Many changes to the menuing structure from the N85, which was a surprise. No WLAN scanning on the home screen, which I use extensively. The compass in maps works well and is a nice feature.
I have always had bluetooth problems with the N85 and certain headphones that I have never had with my N73 or N82. The N86 so far is showing the same bluetooth issues as the N85. This is one area where I was definitely hoping the N86 was going to be better.
I have had three N85's (replaced twice by Nokia for various hardware problems. The one I have now still has some minor hardware annoyances, not worth sending back to Nokia at this time thought. Through three software upgrades (currently 30.019) the N85 NAM is still the buggiest N series phone that I have ever had. Using it has often been an excersize in frustration. I was hoping to really like the N86 and replace the N85 with it but, so far, the jury is out. I will definitely spend some time with it but my initial impression is that I will stay with the N85 and look for something else coming out from Nokia.