I was reading this post and the first thing I thought was "no builder is going to let THAT much out".
I still think that, but, I'll respond anyway. 5 braces. Why? That's what I was taught by my teacher, and by his teacher.
My teacher has since moved to 3 braces, and I've tweaked my bracing to the the point, fortunately or unfortunately, where I can actually install a LRBaggs IBeam. The IBeam was the goal, but I've never installed it. Go figure, I had to do some things to the bracing to make way for the IBeam, and ended up keeping it.
Not unlike Chuck, I can tell you I install 5 braces, and even taper to zero at the ends, but this serves nothing if you don't know what else I do to the instrument - bracing, size, shape, etc., is more like "final touches" and part of the whole, rather than an individual variable. I change the cut of the braces if the instrument is a low g or re-entrant, softwood or hardwood top, etc. It changes per instrument depending on body woods and the sound the client is looking for, a tweak here, a tweak there.
Yes, I can tell you I do all of that, which I do, but if I were to cut and shape braces EXACTLY the same on each instrument, no one would probably notice, including me.
Call it voodoo lutherie (I stole that term from here, Chuck I think), but I know one builder who normally does 3 fan, get a request from a client for a 5 fan (yes, the client requested it). Compared to his 3 fan instruments, the 5 fan lost some volume, but gained in other areas. Yes, there was a difference. There should be with two extra braces on an instrument built for 3. The client loves it, and if he needs volume, he just turns it up, and doesn't even consider the slight volume loss a concession - the overall package wins over an individual insignificant variable.
I can imagine after reading this post, some may say, "okay, volume loss from 5 fan, gotta go with 3," and that's okay, if you play a cheap instrument and installed Aquila's to bring out more volume. I referred to a higher end instrument based of midrange construction, which brings much more complexity to the table as a total package.
Note: I did do an X-brace, twice, but that was for tiples, and you can bet that I adjusted the bracing before gluing on the top of a 6-string.
Aaron