I just bought the Next% as many reviews preferred them to the Alphas
And I know people who prefer the original 4%. I think show reviews are important, but that you still need to try a shoe and see how it works for you.
With regard to the Alphfly, for me there are (so far) a significantly better long distance shoe - the reason, my legs feel markedly less beat up after a long runs (32km). My marathon pace runs feel easier and my legs are less beat up. It’s actually difficult for me to restrain myself from running faster as my run progresses and I have to focus on not running too fast rather than not running too slow to keep pace. Caveat I have not yet races in them, but there is no way I would pick any other shoe right now for my next marathon.