If by how does it sit your talking riding position I'd say this bike puts a considerable amount of weight on one's hands and wrist. I start finding it a little uncomfortable after a half hour or so but I think I'll toughen up over time. With the R and its straight up position I never had any hand issues. That being said I'm overall quite comfy on the bike.
WELCOME TO THE "DARKSIDE".
Check out the Flying Brick K-Bike section of this forum to get advice from other K-Bike Krazies. I'm sure the K12 crowd will have plenty of good tips for which barbacks might work best or anything else specifically about your bike.
Gorgeous bike!