How does one evaluate this lens and others like it - eg Canon 135, Sigma 135? I guess hands on would be ideal, but my problem is that there are many variables to any particular shot, you might nail a shot with a lens and determine it is great, or the reverse and conclude it is not ideal. And I don't just mean f/stop, shutter speed, ISO. Focus ability (in the case of a MF lens), camera body, PP, shooting technique and so on. And for me reading technical evaluations only goes so far. I also tend to discount reviews to a degree - at least in this case the reviewer indicated he's a Zeiss Fan boy, so that helps frame the review.
A friend of mine had a philosophy which he used when learning to play golf. He purchased the most expensive Ping clubs before he started his lessons (Ping beingt he best in his eyes). I asked why? Answer was that in golf there are plenty of variable in play, buying the most expensive clubs ruled one variable out. Can't be the clubs, must be something else.... I don't agree with that of course. But when you can't decide, maybe there's some logic there.