Well, I went ahead and did Brown's Canyon yesterday - twice.
I found a lot of what everyone said to be true - thanks for all of the input. It really wan't quite as difficult as I imagined it might be (at 2100 cfs if the gal at Hecla had the flows right). I did find there was a bit of rock dodging, similar to the Eagel, but it was more impotant to dodge the giant boulders and holes of course! LOL The swirling currents were definitely a different feel the first time down, but easy enough to get used to and account for.
The only real surprise was how short it was. I didn't recall it being so short! We were at Zume Flume before we knew it, and by the time we hit Hecla, I couldn't believe it was already over. We got out, debated for a few minutes, and decided to run it again. The second time through, we parked at Stone Bridge so we could run Seidel's, at the encouragement of the gal counting boats at Hecla and a commercial driver. I am so glad we did, that was a fun, but Twin Falls was even more fun IMO. Not much after that of course, but it made for a longer trip, and if I am going to spend 6 hours in the car, I better get close to that on the river!
Anyway, great fun, brought back a lot of memories of my Dad and I rafting it every summer years ago. Thanks again everyone for the input.