56mm or 90mm ?

So many good points and observations in this thread!

I owned the 50 f/2,. 56 f/1.2, and 90 f/2. Everyone who says that the 56 and 90 are special is absolutely right. But then, the 50 f/2 is also special, because it's so small. This means that it can be a just-in-case lens—you can keep it in your jacket pocket just in case. When I got the 50 f/2, I thought, I'll use this all the time, because I'll take it everywhere.

But ultimately, looking through my Lightroom, I took way more photos with the 56 f/1.2 than with either the 50 f/2 or the 90 f/2. I think this was because I often used it at night and indoors. I made many great portraits of my family members in the evenings, in dim light, from across the living room or in the kitchen. There was a clear use-case for the lens. If the light was right, and I was in the right frame of mind, I knew that I could take a certain kind of photo with the 56, and I really enjoyed using it.

Out and about, the field of view of the 50 f/2 was just a little too close to that of my beloved 35 f/1.4; I found the 35 more versatile, and the 56 more of a useful contrast. And the 90 f/2 was fantastic outdoors, but I didn't enjoy being so far away from my subjects. I like my photos to have a less telephoto, more intimate feeling. To my surprise, I also fell out of love with the look—I took a lot of pictures with beautiful bokeh and then got tired of bokeh. Meanwhile, I discovered that the 56, stopped down, worked well for landscapes and other shots.

If I were to do it all over again, I'd buy the 56 and only the 56. But that's not a normative statement about lens quality—just an observation about my own preferences.