For me, when Wulf died it was the end of an era, but the story went on. Then Johnny died - I was swept up, thrilled, dismayed and bereft, but I loved every minute of it - and as much as I love Carlos, I thought Harrison and MacNeil did an amazing job. I had zero complaints, it was one of the best strips running at that time.
There was loads of potential for great stories with the other dogs, but they just felt like generic sc-ifi stories cobbled onto a continuity, they never captured that sergio leone/clint eastwood western feel that classic SD had.