I just got a Dell AT101 today from an online auction - so far I like it, it has black alps keys, which have (i believe) a tactile actuation point but no audible click, and after that they are linear to the bottom.
They're actually not. There's two tactile peaks in a row — see the black graph here:
http://www5f.biglobe.ne.jp/~silencium/keyboard/html/alpssw.htmlI have a virtually NIB one and it felt crap from new. Stiff, spongey, scrapy, juddery, nothing like typing on MX clears. I don't know what Alps did wrong with that switch, possibly just cheap plastics?
You may find that lube sorts it out though.
The only thing I noticed - the keys don't slide very smoothly …
They're pretty ropey switches — they're from the period where Alps seemed to be cost cutting, possibly to try to compete with the wide range of clones on the market. White complicated Alps is also pretty naff, not a patch on the blue Alps switch that preceded it.
Black was preceded by salmon, which was a lot smoother than black, but far too stiff. Orange Alps should be your best bet, or Matias quiet switches. Brown sounds like the best tactile Alps, but those really are rare. (Brown → orange → salmon → black, with black simplified added at some stage.)