I agree completely. Now, however, after handling a 70-200mm f/2.8, I'm very comfortable with my 180/2.8 Ais.
I also have a Zeiss 135mm f/2 APO Sonnar, which is similar in size, but a little bulkier, a little heavier. Both serve a similar function, so I had planned to sell the 180, because, as everyone "knows", the Zeiss is superior.
And yet, each time I use the 180/2.8, I'm struck by how balanced it feels, what a joy it is to use, and how much I like the images it produces. In the end, I kept both. I use the 180/2.8 for walking around, just enjoying informal, enjoyable photography. If I get serious enough to use a tripod, I break out the Zeiss.