GNU boards are just as well/badly constructed as Lib-Tech. Zero difference. Many people would consider the RC to be a slightly upgraded TRS.
I picked those two over the AB because the camber profile-flex combo is better suited to groomers IMO. The AB has more rocker in the profile which helps with float in powder and turn initiation/looseness. However, to avoid it becoming to squirrelly/unstable on hard (like the Magic, which has more rocker) Mervin increased the stiffness resulting in less playfulness, pop, andvbutterability.
Accordingly, for mostly groomer riding I would go with the TRS/RC for playfulness and pop, while the AB is better for off-piste because of the float in powder and the extra stiffness.
This may be true, but it still should be noted that the AB is a solid performer on groomers and hardpack (dozens of reputable online reviews agree). The rocker/camber Ec2 Rocker/camber is a total blast and a killer option. I own it and I don't consider it "squirrely" in the least. Super-versatile board!