Things that are different than my current 2006 ride...

* 29 inch wheels roll fast

* Geometry has changed a lot (again)

* Suspension becomes invisible when riding

* One-by wireless electronic transmission (two things)

* Tubeless fat tires

* Seat post dropper

* Through-axles front and back

* 200mm disc brakes

did I mention geometry?  It's a different bike

I rode S4 S5 today at my 6 feet zero inches tall  Shorter leg longer torso  S5 is it no doubt