Honestly the first four episodes were pretty good, I didn't think they were top tier episodes but definitely some quality content and based on those four alone my rating probably would've been a four, but unfortunately there was a fifth episode. Personally I thought the fifth episode was pretty much garbage and outside of a few moments about Oliver that I liked, it seemed like the only reason they made this episode was because they needed to make five. That episode alone drags my rating down a star. Also as a general thing about the crossover I thought that for the most part Oliver's arch wasn't handled very well especially in the earlier half. After all the buildup that Arrow did it seems like the 'real' Oliver's story in the crossover was very mediocre and unsatisfying but I'll leave it at that to avoid rambling more than I already have.