Anthem rider here. The suspension design seems to work well (little pedal bob whether pro pedal is on or off), and it is a reasonably light frame (they barely saved any weight with the carbon version). People with small frames get bike weight down to 22lbs without trying too hard.
Mud clearance isn’t brilliant, although I’ve got a 2.25″ Racing Ralph at the back with sufficient clearance. The hole by the suspension in the front triangle collects mud, but it’s not a disaster.
Can’t comment on the Superlight, but I’d happily go Anthem again.
PS – The X1 frame is exactly the same as the X4 etc, so bear that in mind if you stumble across a bargain (e.g if buying an X4 and selling the bits).