there is a noticable difference in the Comp ST and XR+
1. the frame, XR+ is beefier
2. XR+ uses 20mm rear bolts, ever going to bend them on two wheels, ST uses 12mm?
3. XR+ seat has a more clearance from the rear axle, less chance of rubbing your elbows on the wheel
4. XR+ seat vs the ST seat is more confortable. I have yet to sit in a ST Seat longer than 1 hour unless I use a Spring Backrest or Custom Backrest. I
can spend all day in a XR+ seat with no mods.
I prefer the XR+ just for the added mods you can choose from: 120cm rear axle, kinked downtube, extended siderails. not to mention you dont need to
change the front fork to add a Midi Wheel. With only $100 in price difference, you'll be happy you went XR+ over the Comp ST.
my wooden nickel thought