Older B&w 805 (N or S) vs new 705 S3

These had a nasty breakup problem in the upper midrange. It sort of had its own unique texture, but it could also come across as somewhat of a distortion in the upper midrange or ringing.  

You've measured it have you? Can I see the results?

I have a set of 705 S2’s and a set of 805S and I’m powering them with a McIntosh MA352, and I have found a couple of differences between the two. 
The current 705 S2 are very well made and the fit and finish are beautiful. Sound wise I found them to be accurate and very detailed, almost to the point they could be a bit fatiguing at higher levels for long listening sessions. I normally do not play my music to that point, but have noticed it. The bass response is pretty good for a stand mount speaker. If you are looking for deep bass, you will need a sub. I was running my 705’s with a B&W 600 sub and it certainly added a bit more bass. 
I ended up running across a perfect set of used 805S’s at my local audio shop that had the original boxes and papers. The 805’s are wonderful. I have found that the highs are very smooth and detailed yet not over powering or bright and not fatiguing at all. The 805’s seem to have a bit more lower end and they sound really balanced and the bass response is very good, but again if your looking for deep bass, you will need a sub. The fit and finish are really nice and while I wish they were piano black like my 705’s, the cherry are beautiful as well. For the money, I would go for the older 805’s over the 705’s. Especially since the 805’s are the entry into Bowers higher end speakers. 
I hope my comparison helps in making your decision, especially since I ran into this post a few weeks after you posted it. Best wishes and enjoy your music. 

This is a genuinely helpful group. Thx to all.