Well, I have some trail time on a RIP 9 air formed 4 Star XO1 and about the same time now on a 2014 Genius 910. The two bikes had a very different attitude on trail, although I cannot separate the component choices and how that changes things. With the Fox 34 Talas 140 fork, wide rims/2.3 tires, and wide 780mm bars, the RIP 9 was a trail monster. I absolutely loved every grinning moment on it when things were rough, fast and twisted. I rode the 18" size, but still had to use a bit of 'oomph' to get it to turn fast. It felt a bit long, but plush and super, super fun. It pedaled well, but set up the way it was, it kinda was a lazy climber. Not bad , just not zoomy. Some of that was the seat tube angle and where it put me behind the crank more than was optimal for seated climbing. Still I would have one set up with a 130mm fork and 1x11 in my quiver in a heartbeat.
The Genius 910 is quite different. It feels smaller (and has a shorter rear center) and a bit more nimble. It also has the Twin Loc which is very effective as long as you don't mind the lever flipping. I prefer the Genius as it feels more like a long legged XC bike to me yet still is very competent at speed on terrain that would overwhelm a typical shorter travel FS.
I preferred the Genius, but they are both good bikes.