Yes, the TREX seems to be a "flow-detractor" in the sense that it stops the ball, delays play, etc but it is arguably the most dynamic and interesting and unique mech Stern has done in the last 5-8 years and in the sense of the theme, I think is a non-negotiable!
It has 8 way movement
It can catch and release in a static position
It can catch and move and drop on an adjacent wireform
It can catch and fling the ball wildly on the playfield
Pretty awesome stuff!!