DJ, according to my mentor (big time NYC based photographer), there were certain lenses developed by a number of lens makers over the years that never have been equaled since, and despite computer aids probably never will again due to the staggering costs involved. They came into being because those in control had a passion for developing glass with unique characteristics and spared no expense to make them the hallmarks of their companies ... kind of like a car company making a Formula One race car.
These include many Contax lenses like the 55/1.2, 85/1.2, 70-210/3.5, and the 28/2 as well as the 21/2.8, 100/2 and 135/2. These lenses are more than just a stop or so faster than others. They have a set of properties that set them apart as image making tools of unparalleled excellence.
This phenomenon isn't the exclusive domain of Contax/Zeiss alone. The Nikon 58/1.2 Nocti-Nikor is a passionately pursued lens also, as are lenses like the Canon 200/1.8 and the Leica 180/2 among others such as the Hasselblad/Zeiss 110/2FE which can be had still pretty reasonably and can be adapted to a number of Cameras including the N1, ND, and Canon 1DsMKII.
I also am pursuing some legendary Leica glass for use on Canon digital cameras, recently getting a mint 50/2 three cam for a song that is so much better than the canon 50/1.4 it isn't funny. I'm looking for a 90/2 also because my mentor said it's an unparalleled lens that costs less than a cheap plastic kit lens.
Yes, asher, the Contax 70-210 was mounted to a Canon 1DsMKII, and I use a split prism Canon screen to facilitate manual focusing of a slew of Contax lenses.
Yes DJ, I also am going broke ; -) But I think these items will disappear into passionate shooters collections and do nothing but become more rare, thus more expensive. The 55/1.2, 85/1.2 and 21/2.8 have already moved out of my price range.
The 35/1.4 is climbing in price if e-bay auctions are any indication.
BTW, whoever was talking about the Zeiss 45 Pancake lens, I'd advise keeping it. Placed on an Aria, this little package can perform right up there with a Leica M and 50mm.
Here's a high key shot taken with a Contax 645 using a Kodak ProBack 645C and a 110/2F Zeiss lens mounted on it.