I think there a at least three different types of aluminium column stalks on the market.
I've seen the first advertised through the Austian Morgan Importer - but I've never seen one in flesh.
The "Merz & Pabst" Design is the most advanced and machined from billet aluminium. Naturally they come at a staggering price, but retain the intermittent wiper function. Moreover they are available in a multitude of finishing styles: black, polished, flat aluminium and anodised in different colors.
The delicate looking ones from Leberfinger / Morganpark Hamburg have a far cheaper looking finish and are bonded to the plastic of the original stalks.
I'd prefer the stalks that are being distributed through Merz & Pabst. They engage with a reassuring "click" and they are a real joy to touch and operate.
Marian