all things considered it's not really twitchy just kind of stiff and slow, probably because you aren't getting enough momentum or spin from your setups. just work on timing and stuff like that. all your joints should be like maximally extended the frame before you are airborne to get the most momentum. either way not bad atall.
using relax =/= smooth. if the power of your spin or flip is lacking in a trick it becomes much harder to make it look smooth because there's nothing to mask the lack of movement. usually once you've tucked you don't really need to move too much.
so yea it's because you aren't chaining the moves together well, not because you don't use relax. work on getting power out of your setups, just experiment and see what works.