I strongly agree with your assessment of the 340cSE.
It is quite an improvement over the 340c classic. Vocal rendering is much better. As I stated before, the upper mids and highs seem clearer... some have said 'more refined'.

The 3x340SE's across the front have been a great improvement. Moving the 340 classics to the rear has also helped in providing a greater 'envelopement'.

On occasion I would shut off the sub and listen to 2-ch stereo. I have not done that since I got these (late last week), but will this weekend since I'll have a little more time. I actually preferred this way to listen to certain recordings.

I'll also be checking various x-over settings. When I would listen to certain music in stereo (with sub, obviously) I would switch to 60hz, and found things to be a bit more delineated... with the 340 classics. I can only guess that there will be a further improvement in that with the new SE's. I actually may change the default setting to 60hz, since I now have 340's all around. We'll see.

Cheers!

shane