There aren't a whole lot of macro brackets out there. Wimberley makes a good-looking system you might have to apply for a loan to get. Manfrotto has a really basic and bulky model. Really Right Stuff has an interesting rig, but it is really confined. Flexi-neck models just do not hold heavy flashes in the precarious positions that are needed.
The Kirk bracket looked like the best simple fix. Two pivot joints allow a good amount of movement, along with the sliding mounts. It works well in most situations, but with the SB-800 and SB-600 strobes that I use, there are some angles I just cannot get; sometimes I want to start twisting and bending the arms to get the light right. I have ended up carrying a small boom stand with me to reach the hard-to-get-to spots. Photographing pygmy butterflies in saltbush or ladybugs (ladybirds across the pond) in a jade bush requires some deft positioning. One more pivot (or micro ballhead) would fix this dilemma.
Edit (July 27, 07)
After using the bracket for a while now, I can't stand it. The joint locks don't hold up the weight of an SB-800 or SB-600. The arms constantly collapse, so I just can't trust the thing. Kirk can't seem to make locks that work. On my BH-3 head (now on my monopod since I upgraded to an Arca Swiss) the minimum tension knob resets every time I lock the ball. A floppy ball is dangerous, so I hate the ballhead too. I just hate Kirk now. After using Arca Swiss for a couple months, I have resolved some of my anger issues and can move on.