Yup, Instax is much better than SX-70 ever was; of course, I may be biased because I spent 7 years at Kodak working on the Kodak Instant Film System.
Fuji licensed the technology from Kodak around 1980 and was never sued by Polaroid. For years it was available outside the US only. Now that Polaroid has gone 'belly-up' they can also sell it in the US. The technology involved is VERY different from that used by Polaroid.
Wasn't Polaroid instant in its dying days actually a Fuji-made product?