I've had the 1TB, 4K variant for almost a year now. LOVE IT! I constantly use it for digital artwork, 3D sculpting, and sometimes gaming. The pen input is superb, the performance beats the Surface Book I have at work, and it lets me do so much stuff away from my desk. Very underrated machine.
I suppose people overlook it because of its size, weight, thickness, and battery life (that screen manufacturing defect last year didn't help either). These haven't been issues for me. The trade-off for performance is worth it. I am hoping we see more powerhouse 2-in-1 tablet PCs like the 720. I really hate the wall that exists between "gamer" systems that have dedicated graphics and tablets that have integrated graphics. The 720 put a hole in that wall last year.
I am disappointed the 730 is just a CPU spec bump. Really wish Lenovo would upgrade to the 1050ti.