I have a GTS2M and I really like that cube. So is this worth more than twice the cost?
Yes. Will it help you beat your PB? You'll have to try it to know that.
What I can comment on is the quality, colors, setup out of the box, smoothness, no-lock ups, and customizability are TOP notch.
It feels great, and does really feel premium compared to the other cubes (GTS2M and other cheaper cubes) that I have.
It may not be for everyone, but for me, I think it totally lives up to the hype.