I learned from imdb that Arnie put $1.4 million on the table to demolish a building by crashing a construction crane in it. The resulting scene must be one of the best car chases in the franchise.

I also learned that fans were infuriated that the movie undermines the adagio: "there is no fate, but what we make for ourselves". We learn that judgement day is inevitable. Now in the first movie that adagio is never proven. We might just be in a time loop (like in Twelve Monkeys or Looper). In the second it is clear that the future is not set and judgement day can be avoided or at least postponed. I like the ambiguity of the first one better.