It'll be set-up related, without doubt - whilst I'll admit that my DA7800 is smoother than my Ult6700, there is nothing wrong with properly set-up Ult6700.
Where are the gear cables routed along the handlebars - inside front tightening the radius of the cables, or around the outside rear, then under to the front of the bars (better option as it provides for an increased radius on the cable under the bar wrap) - does make a difference?
cheers