Thanks to all for the input. Looks like I'm going to have to just try it and see what I think.
I can't afford to like the Hassey version, so that's out right off the bat. Kevin, I'd love to just get a brighter screen and continue to focus manually focus. The problem is, I could take all day to focus and still not know if I'm focused. And, since I very rarely do "hold still" type portraits, it's even more difficult. With 20/4000-ish vision, correctable only to 20/40 on a good day, it just isn't going to happen. I do just fine with AF on 35mm, but I'm spoiled by 6x6 negs.
Ugh. I don't like my choices.