Ha ha, I hate running and walking. Good or not, I am NOT doing it!!! My aerobics are on heavy bags, stick fight etc. I am too old to worry about staying in fighting condition.
BUT I do know the value of running. I tried it before, it is hard to use doing rounds on bags and all. This is because to kick and punch, then step back and doing it again. You do have a second or two of rest. That makes a day and night difference. The first time I ran two years ago, I thought I was going to die after a short distance. Running don't have a break, that's why it's much harder.
If you are young and train for competition, running is a MUST, but for older folks, for what? Be careful of the hips. it's a lot of load. I did it for a month, I started to feel it on the right hip. My wife had two hip replacements because she did high impact aerobics when she was young and did a lot of fast walking, that did her in.