Canon DSLR and analog lenses (M42, Contax etc.)

The CZJ 180/2.8 Sonnar is one of the better offerings and you'd perhaps you'd also enjoy the 120/2.8 Biometar, Harry, which is much more compact but of similar optical quality.

As for the Meyer 300/4 Orestegor....I agree that it's difficult to find any redeeming features and it's at the bottom of the pile of 300/4's.
The order based on my collection and non too scientific observations;
Pentax FA-645 300/4 ED
Canon 300/4 L IS
Kilfitt Pan-Tele-Killar 300/4
Pentax 67 300/4 ED
CZJ 300/4 Sonnar
Meyer 300/4 Orestegor

 

Well actually, the Biotar 58mm 2.0 is as good as most modern lenses with added bokeh to boast. Regarding dull viewfinders, keep the f at 2.0 for focussing, then turn it to the preset f stop, easy! or liveview if you like To each his own of course. For me it's a hobby in a hobby.

 

It is also how an "automated" Minolta SRT 101 (or any other mechanical SLR and later, a digital SLR) would work. Wide open for maximum light in the viewfinder, then after the shutter button is pressed, the aperture is closed to the chosen value and shutter is actuated. But you are forced to do this manually if you have a third party lens without the "automated" aperture. So we are already accustomed to this kind of "behavior" (or necessity).

 

I was comparing canon to canon not canon to sears, and i said "some 3rd party brands like sears and vivitar, porst and revuenon released some really epic lens."

Revuenon and Porst were brand names created by the geman mail-order company/retailer Foto-Quelle

a few of the lens that were sold by vivitar, revuenon, sears, porst were produced by the the likes of Fuji, Mamiya, Yashica, Tomioka all which had decent quality control and optical designs.