Had Monarch 2016 and 2017 and currently ride Motion. Before that Shinn Monk (2015) which I still have and X-ride 2009.
Monarch is a great board, fast, grippy, loads of pop and it carves nice. The board is stiff but rides quite well in chop when your are in its sweet spot. Must be an effect of the channels. When riding overpowered it needs strong legs and takes quite a bit of energy. It is very solid but not the lightest board.
Motion is easier to ride. Has a lot of rocker (5cm), obviously carves well. I have not found major disadvantages in low end and speed, but would think that side by side the Monarch would win. For me the speed is more than sufficient. It is a very good allround board, you can jump high, it has enough pop for basic popped jumps, you can carve small waves.
I believe the 2009 and 2010 X-rides were similar in flex. My X-ride was way softer than the Motion. My Monk, which is a renowned top freeride board and has more performance than the old X-ride, is also softer than the Motion, noticeably in the tips.
My Motion in motion https://vimeo.com/243509114
There is a carbon version of the motion, the Drive, which is the same shape with different construction and thus supposedly a bit more performance.