Zu Essence vs B&W

How much are you looking to spend? I have owned klipsch and B&W in the past. I feel that klipsch's weak point is their vocals and I feel that B&W strong point is there vocals. I really like the 803s and think it would fit your bill. I feel that in the price range of the 802D there are better speakers (thiel 3.7, Martin Logan spire, Wilson Sophia, etc). But a used pair of 803s will bring a lot of the "B&W sound" with a much smaller price tag.

One thing is to keep in mind what you are use too. The are RF-7s are some what bright and forward. The ZUs might just be too different... But I think B&Ws will out class the Klipsch on almost all areas.

Also keep in mind that a used pair of Martin logan spire are under 5 grand and I think they are a big step up from the Vantage. I had both the spire and 802d in the same room for a demo. The 802d imaged much better but was also more "colored" though the midrange ( and need moster amps). the bass was faster and more controled on the spire. The highs were both top notch!

The Spire would certainly be on my list, vocals are my top priority, i just don't want to be limited in what I can play. If the Spires can handle Floyd and Zeppelin then they may be the ticket.

... larger soundstage and ... smoother more present mid-range

I have not heard B&W 803's, but if your goal is as stated, this is exactly what Zu will give to you - IN SPADES!- IF properly set up. I don't think you can get better soundstage or more present mids than you can with Zu. They are phenomenal in this regard.

That is what I have read, anyone compare to the Logans

I would advocate that you ask your dealer to let you borrow a pair of Von Schweikerts and try them out with your equipment and in your room. If you pay close attention to speaker placement I would be very surprised if they didn't sound awesome for the type of music you listen to.

Also, do any of your local dealers carry any of the French speaker lines: Focal, JM Reynaud or Triangle? All of these are somewhat different, of course, but I find that all of the French speaker manufacturers create a lush yet detailed sound that is stellar for vocals and instumental music.