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.
I unfortunately have had a very bad experience with Lenovo support last year and am a bit wary or their support.
I purchased a Miix 700 which I originally thought was pretty good and unfortunately had an issue where the keyboard would drop letters randomly and made it difficult to type with. I found out later that all seemed to have the same issue and there was no fix for it. You could get a replacement but they all acted the same way.
My real problem came when after a power outage the battery would no longer charge. In the end it took two months longer than it should have and the tracking on their site was useless as it stated six months more since their system adds six weeks whenever one of their tech touches it. I had to call to somewhat of an accurate update but they didn't really have many specifics. I finally received it back and my tablet was an unstable mess replete with random graphical glitches and crashes. I was able to get it back to a mostly stable state by updating drivers and such and turning off any power saving (It now refuses to wake from sleep) but it still occasionally flips out. I am tired of dealing with their support with this issue so I have decided to live with it until it is time to replace it but the whole experience has soured me on them a bit. It is unfortunate, I do like what they have to offer.