I loved the original, when I had only seen the TV cut which doesn't include the protagonist committing rape. I've seen the full version all of once and that just broke it for me.
I have the sequel on my to-watch list, but will be starting it off in a guarded manner.
When was that? Last time I tried it was a couple of years ago.
As for the difference, outside of Spain the conjugation of Vosotros (you, plural) isn't used, but speaking to strangers is much more formal. Also, there's a lot of vocabulary differences which can be confusing for non-native speakers.
Good luck with your learning, it's a great language :-)