Now that it is open to the public I can toss out my 2cents. I really enjoyed the attraction...A LOT!!! I was among the worried they were going to ruin the last great "Walt Disney" classic. I can now say they didn't.
I think they did a AMAZING job on keeping the feel of the attraction as it has been for almost 40 years while adding in a few new touches to stop the "where is Jack?" run on City Hall. Do the changes screw up anything...a little, the movements of the 3 Jacks make the old AA's seem way out of date. Will I never go on it again because of what they did...not a chance! It is still the same attraction just with some added stuff. I think this change is less then the PC change of the mid 90's (which they did adjust with this change).
I really enjoy the small things they added. The chess game, powdered wig, the new effects in the treasure room. But the Davy Jones effect is the biggest change that just makes it all fit a little bit better.