Largely because of the comments I've read on this thread (and some from others) I got the Nuforce Edition board for my BDP-93 this week and have been giving it a workout.
This is my first post, and I just wanted to give my impressions on the upgrade board and to reinforce others, like me, in saying that, no, you're really not crazy to spend almost as much on an upgrade as you did for the original player. IMO it's a darn good improvement, and worth it.
Fortunately I had the opportunity to get used to the characteristic sound of the stock BDP-93 over the last few weeks (very good I might add), via all my favorite and familiar CD's and SACD's, so I do have a basis of comparison. I'll just say, right off the bat, that the sonic differences were immediately noticeable and an improvement.
I really liked the detail, separation, and soundstaging of the stock 93, though the vocals were more laid back than my previous player, a Philips 963SA. My main issue, and the one that led me on a mod search, was that the BDP-93 had a bit too much of an edge, leaning toward stridency, for my tastes.
I've found the Nuforce board to have a much smoother presentation, easier to listen to, while retaining all of the soundstaging and separation, and improvement of subtle detail. Both instruments and vocals have more presence and texture making then seem more realistic, and the vocals are a bit more forward now.
For any of you who have the same sonic concerns I did, I would encourage you to give this Nuforce board a try, especially considering the 30 day return policy.