Thanks for sharing this comparison. It is the only comparison I’ve been able to find addressing the differences in cuts. Seems the main difference of interest are a few scenes of dialogue relating to the political philosophy of the film.
Planning a rewatch soon as my only viewing was a very low quality dvd release which really brought down my viewing experience. The film did win me over enough by the end that it has continued to sit with me in a way that warrants a rewatch.
Here’s a comparison I did between the two versions released on the Arrow blu-ray, the Italian/English cut versus the extended Spanish cut. Unfortunately, the extended Spanish cut looks considerably worse with less detail and the distinctly filtered/smoothed look (mostly noticeable in darker scenes):
