So I put 1501 (not sure how I managed that exact number, but honest to god that's what the trip odo says) on the bike this weekend and I think I'm ready to finally give a thorough evaluation report on the risers.
If you are going to do any long distance riding (>300 miles), and you aren't 100% comfortable with the current bar setup....you want to put these things on your fz6. I did two 500 mile days and two 250 mile days, the 250's weren't much, but at the end of the 500's my butt was killing me (need to get a new seat before I do any more long trips), but my shoulders, arms and back were just fine. Before I put the risers on, a "short" 100 mile weekend trip would leave my back and shoulders sore and tense. Like I said earlier, the biggest improvement that I noticed, was that I no longer had to sit as close to the tank, I was able to sit further back in the seat and sit straighter. On long trips this makes a huge difference.
In regards to performance, I honestly haven't noticed any difference in how the bike handles. One of my biggest reservations about buying the risers was that I thought I might lose some of the bikes sharpness in the turns. This turned out to be completely unfounded. I took the bike through some pretty twisty routes at speed and with 50lbs of gear strapped to the back. I never felt like she had lost any of her response (maybe I just wasn't taking the corners as hard as i thought before?).
The only thing that is really different, is that you can't tuck in behind the windshield quite the same as before. Before, I used to be able to lay down on the tank and still have my arms at a comfortable angle to the handlebars, now it's a little bit uncomfortable. I only really noticed because on the really long stretches, when my behind started to get sore, I would try and lay down on the tank to get my weight off the seat. I'm pretty sure putting in a better seat will remedy this and remove any need for me to lean that far forward.
I think what I'm really starting to appreciate about this bike is the polymorphism (any other developers out there???). With a little bit of tweaking you really can turn an FZ6 into just about anything you want. Plenty of people on this forum have turned theirs into race bikes, some into streetfighters, and some into touring bikes. It really is flexible enough to do any of the above, and I don't think i fully realized it's potential until I took it on a long haul this past weekend. I guess my final thoughts are these, I love my bike more and more the longer I have it.