I'm running an older pro taper on my Balfa that measures in at about 810mm (on my unofficial ruler). I love it, never had an issue with it, but I agree with the orange/red colouring comments. Matches my bike perfectly though =]
They are stiff, and for some reason the ends on mine are sharp (I put some screw-in bar ends on it) but they work better than I expected for a bar I picked up on a whim for $20 at a community sale.
How strange. I found the b52 I have really flexy. The red on the answers isn't the greatest because of the finish before anodizing. Shot blast is it? To spread the stresses.
The next bar I'd like to try is Renthal 780. They have a different sweep which I'm interested to try. Unfortunately I hate the gold colour - wish they did a black version.
I ran it on my XC bike (trek marlin) and while slightly too wide for most tight trails it worked great. Made it a bit more of a trail bike though, definitely less XC stance.
You will need the large stem (can't recall exact mm) but in my case I had a spare unicycle laying around that I traded my LBS for a decent stem that fit. =]