I made the switch!
After running a 1998 FXSTC for two years I got a 2008 FLHX with 14000 miles.
The STC had V&H radius pipes, SE tuner, stage 2? I think Cam, different tanks, custom paint (red base and deep red flames, quick detach sissy bar and windshield, and all the bolts are capped. All of that was put on before I bought it so I'm missing some stuff I'm sure and I'm not sure about the actual cam size.
The FLHX is another story, it hasn't been touched. It has Rinehart slip ons and the bolts are mostly all capped. I got some bags with it to go on trips with so no need for a tour pack. It has a back rest for me and the lady too.
How do V&H radius pipes sound on a FLHX compared to what my STC sounded? It'll be a while but I really liked the sound of those pipes and the new one is QUIET!!!