I think the 85/1.8 is a great lens for the money. I once owned a Minolta 85/1.4, so I can appreciate the benefits of a super-fast telephoto, and since the Canon 85/1.2 is even faster, I wouldn't try to talk anyone out of getting one if they have the need. But for my uses, the 85/1.2 is just too expensive and HEAVY. If I was unhappy with the performance of the 85/1.8, then I might re-consider the 85/1.2.
You could always save the cash and try the 85/1.8; if you didn't like it, the used market is quite good for this lens.
--tom