The AD's were a genius in marketing in the 70's when the US distributors of the Austrian "Puch" brand, decided to sell their bikes in the US under the old and impressive sounding "Austro Daimler" name (Complete with the very classic looking graphics and paint finishes) that had its storied roots in a already long defunct European car company.
Like the bikes from similar companies I mentioned, the AD bikes were solid and reliable bikes that satisfied the needs of most riders of all levels.
In reality,the brand isn't really more exclusive than Peugeot, Motobecane, Bianchi or other similar mass production manufacturers from Europe, if one will look at its model rages offered back then. Maybe a bit better with some of their higher models, but nowhere near more "artisan" brands like Colnago, Pinarello or Masi.
AD did compete with its bike at the pro level with well known pro riders like Jonathan Boyer in the late 70's/early 80's.
The AD brand was resurrected a few years ago and now the bikes are coming from China. The new, modern (mostly CF) AD bikes look impressive enough and are covered with big AD graphics proudly shouting it its brand name. It proves that the name is still quite impressive sounding, even to modern cyclists.
......JMOs.....