IMX is far superior. If you were comparing it to the Avid, it'd be a little closer. The Rage is made from the same material as the Avid, but they have different tapers. The build quality isn't even close between the two. I actually thought the Rage was one of the more disappointing rods St Croix has produced in some time. The handles are way too short, which makes the rods very tip heavy. They have super cheap guides that you'd find on a $30 Berkley rod. They're just an all around disappointment, which is sad considering the blanks are pretty dang nice.
Agree with the above, IMX any day of the week over a Rage.