So today I had time to shim the needles in my carbs. I used the instructions posted back on page 1 (I think) of this thread. They were great, including the Suzuki part numbers for the shims which I was able to order from bikebandit.com and get a couple days later.
The difference was huge. Now I can cruise along at light throttle at 3000 rpm without the surging. It's smooth as glass. I'm still getting a little bit of popping through the exhaust on closed-throttle decel but it goes away if I barely crack the throttle. I think that I'm going to upgrade the pilot jets to size 38 and hopefully that will take care of it. I feel like I'm very close now to having it run the way I want it to run.
I think that when the slides are down and the needle seated and it's just on the pilot circuit, it's still a bit lean. Hopefully 38 pilots will address that satisfactorily.
I also noticed that on a long closed-throttle 4th gear decel from freeway speed to stopped, it did a long-smooth pop-free decel until it hit about 2500 rpm and then BLAM through the exhaust. What I think is happening (and I could be wrong as I'm no carb expert) is that it's a little rich on the overrun down to a point, probably where the pilot circuit kicks in at which point it goes lean and introduces enough air into the exhaust to explosively burn whatever unburned fuel is in there at that point.
So I'll update when I get a chance to get the new pilots installed. I think that will save me from having to spend $80 on a DynoJet or Factory Pro carb kit.