I've had 2 pairs of SPI's and I like them.
Pretty light and responsive. I don't hit the park so I liked the long high-back and the stiffness. On my old pair, I did have issues with the barrel ratchet not releasing easily. I had the same issue with my new pair for the first few days, but not since. My theory is that the teeth on the ladder straps just needed to "round off" a little.
That said, I don't have much experience with the higher end bindings that are always recommended on here, so "light and responsive" is pretty subjective.
Other than the ratchet release problem on my old pair, I've not had a single issue. No hot spots, no adjustment issues, nothing broke or is looking worn.