Yes I do have 600i's and 1000i's here right now. There will be a full review online in about two weeks, but the short story is:
The Final sound speakers are a very different flavor of Electrostatic
panel...
The closest I can describe them is that they sound very similar to my old
Acoustats or even Quad 57's. They are a very mellow speaker compared
to the Summits or Vantages.
I was not very fond of their sub, and would call it more of a home theater sub. For a thousand bucks it's ok, but I would probably go with the ACI titan.
I had great results just running them full range and using the REL B2 crossed over at about 38hz.
They were very pleasing but did not have the dynamics or resolution of the Summits. I know I may be biased, but I had the Finals here for three months before I got the Vantages, so I could have easily pulled the plug on the ML speakers if I would have preferred them.
The one thing the Final does incredibly well is coherence. The Summits go down to about 200hz before crossing over to the woofer, but the Finals go all the way down and just roll off at about 40hz.
Don't get me wrong, the Final is still a good speaker, I just don't think they are as close to being a "do everything" speaker like the Vantage or Summit. However, some people will find the current ML speakers "too forward" or "over detailed". For those people I would definitely tell them to check out the finals, specifically the big ones.
The Final is a somewhat easier speaker to drive and works with anything.
I saw the Final as more of a speaker like my McIntosh 275 amplifier. It is not the last word in dynamics, extension or imaging, but almost everything sounds great when played through it. I did not find them anywhere near as exciting as the Summits, but they are a very freindly speaker. And they look really cool too.
Honestly, Ive never heard a panel speaker I didn't like in one way or another. I guess I just like the Summit and Vantage so much, it's hard to get blown away by the others.
But as with anything, you need to find the flavor YOU like. You may hear the finals and think I'm nuts, that you like that a lot better. I'd say listen to both and I guarantee you will walk away really preferring one over the other.
I hope that helps.....