Hi Rob,
I have a 2000 Fat Boy with a Champion kit (straight axle, not independent suspension). I cannot speak for the Roadsmith ride, except to say I hear great things about it. But I can tell you that just a month ago there was a group of us riding the Dragon --- 318 sharp curves in 11 miles in the Smokey Mountains. Believe me, my trike handled those curves with ease! No doubt the TriGlide would too, though. In our group that day we had a Stallion, my trike, a VTX1300/Champion trike, a Road King, and my husband's Street Glide. On my trike I was easily "pushing" my husband and his two wheels around the corners when I was behind him -- and believe me he is not a timid rider!
I like the TriGlides, don't get me wrong, but there is nothing wrong with converting Lyn's Street Glide with a kit. Neither option is right or wrong---it is personal preference on the vehicle in question.
Nana