Positively not clicky, though the interaction between the stem and the tactile leaf does cause a faint click. They're a pretty scrapy, noisy and rough switch even when new. Nothing like the silky smooth and precise blue Alps switch. I did use another tactile Alps board (orange or pink I think) and that was much nicer, but opinion varies on whether black Alps really was worse than earlier tactile variants. Probably needs some of that Japanese Alps lube.
Anyway … see
http://deskthority.net/wiki/File:Dell_A ... switch.jpg — disassembled black Alps from an AT102W.
The folded sheet of metal lying on the case at the top left is the tactile leaf. The slider snags on this, and the process of forcing its way past the protruding "hooks" gives the tactile feel. The construction of this leaf is critical to feel, and this is what other manufacturers keep getting wrong (why XMs are balky and Fukkas ping so much).
The click sound is caused when the slider snags on the leaf and pulls the whole leaf forwards (front and back together), and then twangs it back against the case once it clears the hooks. This metal-on-plastic impact gives Alps switches a more distinguinshed sound than Cherry's plastic-on-plastic mechanism.
You can see four side tabs perpendicular to the rear half of the leaf. The bottom two (to the right) are always present. The top two (on the left) are present in tactile switches, and they ensure that the switch doesn't click, by preventing the leaf from being pulled forward – the leaf serves only to snag the slider momentarily. There used to be some nice diagrams showing how this worked. We need someone to render some Alps switches in 3D to show how they function.
The snag approach is also why there's so little pretravel on Alps: you can't build up force smoothly this way.
