I'm a businessman who types a great deal.
I like my tools to max my productivity. It's time for a new keyboard... I think.
I've been using an Avant Stellar by Creative Vision Technologies with ALPS keys the past few years.

What I don't like with the Avant Stellar is the loud noise that's annoying to people when I'm typing away while I'm on the phone with them. (I have no idea how much I will or won't like the lack of auditory feedback if I go to a silent or near-silent keyboard, if I even find a quiet version of a KB I like, but I would like the option of typing without the person on the phone knowing that I'm only half-listening to them and that I have more important things to do at the same time.)
What I LOVE, LOVE, LOVE about the Avant Stellar is the extra section of 12 programmable keys on the left side! (The F keys are the extra ones. The SF keys along the top row are the normal Function keys.)

I'm so used to those extra keys by now that once I get any other keyboard I'm going to have to get a separate keypad to serve this purpose.
Note that a few years ago I tried the Unicomp SpaceSaver and really hated it. The force needed to depress the keys seems ridiculously demanding to me. (Not to mention the remarkably lousy workmanship.)
I'm hoping to find a keyboard that has significantly better response than the one I have now.
I'm mainly considering either a RealForce 103UB variable or "something" with Cherry blue MX keys. I'm only into 103/104 layouts.
I don't know what I'd go with for a Cherry blue keyboard, though. I know I don't like the Das or most others I've looked at.
I noticed a comment on one of these threads saying that EliteKeyboards has announced a near-silent keyboard, but I don't see the actual thread and I don't see anything about it on their site. Their site does, however, say to watch for an announcement of a Cherry MX mechanical keyboard in Jan/Feb (nothing about it on their site as yet).
Well, what's my question? Yeah, well... I guess I'm just looking for any advice or feedback that might seem worthwhile.
How much better is a RealForce or a Cherry blue MX likely to be than the ALPS I have now? What's the lack of auditory feedback do for speed and accuracy in most users' experience? Will I even find a quiet keyboard I like without compromising on responsiveness? Do I want to go with the Topre of the RealForce or the Cherry blue MX and, if the latter, what manufacturer?
Thanks!
EDIT 2/6/11 10:10 PM ET: Extra keys and programmability are no longer considerations; I'll use a separate keypad for that. Also, I realized that Cherry blue are noisy, so I'm open to other Cherry that are quiet if indeed lack of auditory feedback is not a problem.