Some more random thoughts on the center speaker issue:
1) I've noticed that when all the tweeters of the LCR (+ Wides in my case) speakers are of the same height and approximately ear level, the coherence and smoothness of the sound stage just snaps into place. The small center speaker (Electra 1008 Be) is mounted so that it's tweeter is at the same height as the fronts. However, the tweeter of the Electra 1028 Be FS is much lower than my fronts so the only thing you can do is put a kalso at the front of the speaker so the tweeter is angled slightly upward. I think this arrangement is less than ideal.
2) A friend of mine had a tiny Focal Corus speaker that matched the rest of his speaker set. Although it was tiny, it produced a big sound and I didn't find anything wrong with it. A salesman convinced him to get a huge Paradigm center speaker. I've listened to the system and I can't detect any improvement. Theoretically, the sound should have deteriorated cuz the center is no longer the same family (or even brand) as the rest. In other words, insofar as the center speaker is concerned, size seems to be a much lesser consideration. In fact, are they purposely designed to be small? Does that produce a better sound for vocals? I don't know ... yet.
3) I still think that theoretically, all things being equal, vertical speaker is better than a horizontal speaker, no matter what the purpose of the speaker. That's because of the comb filtering that the horizontal speaker produces and that is well-documented. In our experiment, however, all things were not equal cuz the drivers and crossovers were different. It seems like those were enough to offset the innate advantage of a vertically-oriented speaker.
