Just a personal anecdote on my jump roping experiences:
I live in New York city, where it's been really cold and running outdoors is not really an option (unless you're ultra hardcore about running, which I'm not).
For the past 3 weeks, I've been jumping rope, doing burpees, and doing Tabata thrusters as my sole forms of cardio. My routine is as follows:
5-6 rounds of 2 minutes
30 seconds burpees, 30 seconds jump rope, 30 seconds burpees, 30 seconds jump rope
45 seconds of rest in between rounds
I try to do this three times a week
Tabata thrusters
4 minutes total, comprised of 8 x 30 second intervals
20 seconds Thrusters, 10 seconds rest
Thrusters are basically squat + shoulder press with DBs. I've been using 25lb DBs.
I try to do this twice a week
I have noticed a significant improvement in my conditioning because of this regimen. My body composition has also improved remarkably. Just wanted to throw this out there, in case anybody's looking for something new.