I tried to read the 5YL run as it came out since I worked in my parents store. I stopped after a few issues, just didn't grab me. One day I realized we still had at least 1 issue each of the first year so I brought them home and read them all at once and it was fantastic. I think the biggest turn for me was Tenzil Kem in issue 11? or you may know him as Matter Eater Lad. anyway once it clicked for me I couldn't wait for the next issue.
I don't think it even tried to be new reader friendly and just said figure it out or read something else. If you stuck it out you remember it as a great run but it takes some effort. I knew pelenty of Legion fans that thought it was bad, though I think it was maybe the best Legion run it was very polarizing. It basically convinced me Levits owed Giffen a lot of credit for their run. I feel like Giffen however bad at dialogue he is was a lot of the ideas.