Tiagra shifters on the Jake is definitely a nice upgrade. I was surprised to see they went with a solid color instead of painting the stays black. I'm especially excited about the carbon kona p2 on the JTS.
The Major Jake had carbon seat stays, the JTS was all aluminum.
On the new MJ they've either painted over the seat stays or maybe gone with the full scandium frame from the Major Major...I'm curious myself.