I saw a guy that I work with yesterday and first thing I do is ask him if he's been riding any. He's says that he had crashed his bike going about 55 mph do to high speed wobble. He's OK but the bike will need some work. He took the the swingarm off and the bearings were destroyed. He's under the impression that the worn out swingarm bearings is what causes the the wobble. If that's the case then everyone should be ponying up for a brace to avoid this problem. Right now, Bagger Dave's looks pretty darn good to me.
What does the Bagger Brace have to do with worn out swingarm bearings? If bearings are bad and the swingarm is loose and allowed to twist, the brace will not help. IMO.
Also with bad swingarm bearings, the will not only twist axially with the bike but under load from the chain or belt the swingarm will pull forward on the dive side causing the rear wheel to steer a bit. Kind of like bump steer on a car, but from the throttle in and off again etc.
From what I've read, most touring bikes in new or good condition will only show this deathly trait at triple digit speeds like Hoist said. I actually tried my '08 SERK this year at Sturgis to see what would happen. I was riding solo and was able to do both left and right hand sweepers at over 100 for short periods. I found nothing that seemed to be the wobble, so on my '08 with the upper front link it may be better than the previous '07 and earlier models.
I'm not saying that a bit of bracing of some kind wouldn't hurt the "feel" at normal driving speeds and maybe I would notice a bit more sure footedness in the low speed curves, but I'm not having issues now anyway. If I were to ride a bike like mine with a brace, I'm sure I may feel something different and eventually decide to bite the bullet and do one.
On the other hand I've ridden bikes without the IDS and find them very choppy and jerky at lower rpms in town type riding and I'm very glad I have the IDS on my '08. If I were one of the guys without it and rode my bike, I'm sure the difference might be worth the $300 to get one. In my opinion the brace is like the IDS, at least for my application. I"m happy with the way mine handles now and it still feels tight and very controllable to me.
I guess you could compare it to the handling differences between a '96 Caprice and a '96 Impala SS. Each are safe, but the Impala has a higher tuned suspension and could out curve the Caprice with one wheel tied in the trunk. I guess at my age I'm more a Caprice kind of guy rather than my earlier days being an Impala SS kind of guy.
Sorry for rambling, but as usual my fingers got to moving and I couldn't stop them...
