That lens is so large as to be nearly impractical. And sometimes bigger is not necessarily better. Don't forget that you can get the same amount of blur with a smaller aperture lens focused closer. In this case, of course, the subject will be larger in frame for the same amount of blur, but this is not always a bad thing, and when focusing on subjects closer, often the smaller aperture lens is preferable to keep the blur from turning the background into unrecognizable mush.
I have my own story about this. I do have my dream bokeh lens. An English company named Dallmeyer made a series of lenses called "Super-Six", so called because all use a double gauss design of six elements in four groups. These lenses are legendary for their very characteristic bokeh. The series runs from 1 inch to 8 inches, all f1.9 except the 8 inch, which is f 2.0. I first bought a one inch, then was fortunate enough to manage to get a four inch. That is 102mm f1.9, relatively fast. That lens was, very unfortunately, stolen. Later I stumbled across an 8 inch and managed to get it. This is a 204mm f2.0, which is very fast for this focal length, and more so for a double gauss lens that covers 6"x9". It is fairly monstrous, weighing in at around eight pounds. Handholding it is like lifting weights.
While the 8 inch is exceptional and much more valuable than the 4 inch, There are many situations in which the wide aperture at that focal length is just too extreme. I have to stand so far back from every subject to NOT blur the background into nothing that it is certainly less useful than the 4 inch in many situations. Granted, the 8 inch can do things that the 4 inch cannot, but it is also a difference of a lens that is easy to handhold and transport at about one pound, compared to a monster that takes up the whole camera bag and weighs eight times that. The 300mm f2 would give you a few exceptional shots, and most of the time you would simply leave it at home.
Here are a few examples, first three shots with the 4 inch and then three shots with the 8 inch