I picked up most of the OB books at the Christmas sale. I keep toying with running the game, as the last game I ran was Shadowrun, and Penance seems a perfect setting for that type of game.
Then I run across the calendar, with its bizarre short seasons, and all of the science classes I've had bring my interest to a screeching halt. I think the calendar and the wonky side effects is the thing I would most like to see gone from an updated version, even more so than the art that seems to try to make it feel like a horror-genre game.
I am actually not sure I'm looking forward to a different mechanic for the prestige races. Asking any of the spellcasters to take levels in something that doesn't advance their caster level, unless it has very significant other benefits, just never works around here.