I have the 150mm lens, not the 180mm lens. I too would not say the the 150mm is "meh" but since I do not take portraits the 150mm lens does not get used much. If I were in the position of buying a lens in that focal length I would buy the 180mm lens based on all that I have read.
The 180 is, optically, pretty spectacular. But whether you choose it over the 150 depends on how you intend to use it. The 180 is longer, heavier, and especially *front* heavier than the 150. It's great for studio portraiture, where the camera is on a tripod--but for portability and use in the field, particularly handheld, I always carry the 150. With the 150, you'll get 90-95% of the the performance of the 180, at about half the cost (or less), and only ¾ of the weight (785g vs. 1075, for the CF versions). If you're shooting digital, you *can* see some differences between the two, with the 180 coming out, as I said, superior. But you'll really only notice them clearly at 100% or close to. If you're talking about normal viewing resolutions/sizes, or you're shooting on film, I think the differences will be a lot more subtle.
My 150 was the second lens I got after my 80mm--and I got it really cheap, because the plastic trim ring behind the focusing ring (which keeps it from sliding down the lens barrel as you're using it) was cracked, which is a drawback of the 150mm CF, as this seems to be a fairly common problem with that lens. I had a new one 3D-printed, and while it's not as glossy as the original, it really blends right in and it has worked perfectly.
So when I did manage to land a 180 at a very good price from my favorite dealer later, that's why I've kept the 150 even though it seems a bit superfluous since I've also got the 120mm. My small carry-around kit for field use is the camera with the 80mm mounted on it, and either the 50mm or the 150mm in the bag as my second lens. The smaller size and weight, and better weight distribution, make the 150 better for that purpose than the 180.
But yes: if you want to *know* you have the best quality lens you can get, if you are printing really big, or you can notice more subtle differences than I can in small or medium-sized prints, and the size/weight/price aren't an obstacle, definitely go with the 180mm. It might be *the* best Hasselblad V lens ever, and from reading online, it seems I'm not the only one who thinks that's a possibility!
