That's a show I watched week by week, and I wonder if I would have enjoyed it as much binging it. One of my top 2-3 favorite shows for sure.
It really was all about the character development, especially the minor characters. I actually found the character of Don to be rather uninteresting by the end, once his background is all on the table, I found myself caring about him less, other than how he impacted other people. Maybe that's why some people thought the last couple seasons dragged, because the Don story didn't carry the series that much.
I really found myself interested in Roger, Penny, Pete, etc much more than Don as it went on, and trying to read what was going on with them. The arcs of even minor characters was what really made that show fantastic to me.
The series also has my all time favorite episode of television ever, "Shut the Door. Have a Seat." the season 3 finale. Amazing episode, just electric.