Right as usual, Mag. I had the opportunity to audition both the 340M's and Studio 40's in my home before I made my decesion. It's been awhile so I'll try to stick to what I'm sure I remember.
The 40's went lower for sure. I had a bit of a preference for the 340's in the mids and highs but I would have been happy with either choice. They were both very good. Both my wife (Her opinion was much more important in this than mine) and I liked the looks of the 340's better. Black just went so much better with our red oak mission funiture.
Payment came strickly from me (my opinion was much more important
) and the price difference was substantial even with a discount from the Paradigm dealer.
The Studio's did not have a better sound stage than the 340's. I can't recall preferring one over the other but the 340's are excellent in this regard.
As to the question of the 340C's ability to handle dialog. I'm your best source of info on this one. I have a hearing deficiency centered around 1khz. That's roughly the mid-point of the human voice. The 340C is the best I've heard anywhere near this price point. I have heard good center speakers that cost lots more but I am thirlled with the 340's ability to handle dialog.
I did not audition the 470 or any other Paradigm center so no comment on that.
Keep us up to date on how your search develops.
David