Though to be fair, maybe this might depend on the difficulty you were playing on? Having played on Hard/Unknown in Xillia and Chaos in Graces, I did feel that Xillia was much faster than Graces in general, and it was much easier to take enemies out. When you level everyone up in Xillia and perhaps get everyone to a point where they're maxed out vs Graces' Lv 200 characters, Xillia certainly does feel faster.
Xillia is certainly slow at the beginning like kayos said, but it takes time to get movement and speeds high enough to make things feel somewhat faster in terms of movement and battle pacing, as I had detailed somewhat
here.