Ok, with this digikey package I now have in my possession all of the below:
Cherry blue: just as others have described, a perennial favorite and its easy to see why. Fairly light touch with bump (resistance that 'gives way'), and a soft audible click. Click is much softer than buckling spring, though if you type fast, in combination with bottoming out the keys you could still raise a bit of a racket if you wanted to. Light touch, easy to bottom out. They seem as light as the browns, only with an audible click. [update: lighter than the browns, and with a soft click. I'm torn between these and the browns. I'll likely keep both boards in the house]
(Old style cherry white: clicky, tactile, barely distinguishable from blue, but there
are some differences in the internals) [update: after typing with them somewhere I'd say they are just a little clickier and have a tiny bit more bump and resistance than the blues]
cherry brown: I became a fan of these for about a week. They are as everyone describes, bump, no audible click (tho a clack if you bottom out), fairly light touch. The browns are comfortable and fairly quiet for a cubicle. Easy to bottom out, which after a while (since I pound the keys) took its toll on my fingers. Kind of like "runner's knee", I was at risk of developing "typer's knuckle"! If you have a light touch you may like these a lot. [update: after some use of other boards I've returned to these as a favorite. I'm torn between these and the blues]
cherry black: no bump, no audio, fairly light touch. They are described as "linear" resistance but in actual practice I'd call them "progressive" resistance. Okay, I don't know why everyone dumps on these on this forum, other than that mechanical switch purists obviously have a clear bias in favor of audible clicks. The blacks suit my typing style quite well as far as I can see. The tactile bumps on the other cherry switches are hardly noticed anyway when you type fast, and the audible clacks only annoy the cubicle neighbors. In the blacks you have mechanical smoothness and springy fluidity, I rather like them, and they let me pound on the keys at will. If the browns are a quick run, the blacks are a refreshing swim. Smoooooooth. [update: after some use, I did wind up finding the resistance a little bit tiring. I went back to the browns]
("New" cherry white: bump, but no audio, like the browns -- but compared to browns then, I dont know if the bump is more pronounced, but the spring does seem stiffer, no question. On these I might actually tire out my fingers after a while. Especially my pinky. But it seems to me these were perhaps made for special keys like the spacebar where they sometimes install the stiffer springs, or maybe for specialized application in point-of-sale industrial keyboards. At least thats what I'd assume after using them!)
So my favorites right now are the blacks, with the browns a close second. I hope thats not sacrilege
[update: after using various cherry boards for a while: like nearly everyone else on these boards, my favorites are now browns and blues
]