Hypothetically I might have the option to get either lens, both for the same cost locally. 200mm f/1.8 has the original 1.4x and 2x extenders. Both look to be in excellent condition.

Besides the obvious just get them both, and it might be an option. Which would you get? Both would get plenty of use from me, I've always loved the 200mm f/2.0 IS. Have used it on a couple of occasions and it is an amazing lens. But I certainly am not apposed to the 200mm f/1.8 and have always been intrigued by it.

Likewise, the 50mm f/1.0 has always been a dream lens for me. This and the 85mm f/1.2 is what inspired my screen name way back in 2008 or 2007. Because I love fast lenses.

Which one would you choose? I do technically have the option for either. Maybe both if I ask nicely.