If you ask me, yes it is, in my non-expert opinion that is. I love jumping rope for a number of reasons. The most obvious and important for me is the savings in time. They say that 10 minutes on the jump rope gives the heart the same workout that 30 minutes of running does. When I heard that, I thought it was bullshit. Then I tried it and I was a believer. It's a very intense 10 minutes, that's for sure.
I also like jumping rope because it is a far more complete workout for the body than most other forms of cardio training. I never really noticed this until I decided to take the famous Royal Court (Hindu Squats, Hindu Pushups, bridging) and insert a period of jumping rope before each exercise. The routine looked something like this:
2-3 Minutes Jumping Rope
100 Hindu Squats
1 Minute Jumping Rope
50 Hindu Pushups
1 Minute Jumping Rope
3 minute Back Bridge
By the time I got done with the second interval of jumping rope and proceeded to the pushups, my arms were so tired that I thought that they'd fall off at the shoulders. It didn't get any better when I got to the final minute of jumping rope. Even my abs could feel the workout. I didn't get this kind of intensity from the Royal Court alone. Plus, the rope builds timing, coordination and balance. I think only swimming could match or surpass the benefits of proper jump rope workouts.
The hold up in many cases is learning proper technique. Otherwise you're doomed to tripping over the rope endlessly. Once again, I'm not an expert at anything and least of all jumping rope but I do know that proper technique is seldom taught. The rope should only come up to your armpits when stepped on in the center. Any more should be knotted up at the handles. Your shoulders should be relaxed, elbows shoulder-width apart, and the rope should be held farther than that. Don't grip the handles too tightly. Feet should be together and up on the balls. When you jump, move the handles at the wrists, not at the elbows. Jump only about an inch off the ground. Any more is a waste that will fatigue and cause you to trip on the rope. Move at a pace that is comfortable for you.
Another issue that hinders progress with jumping rope is selecting the proper place to do it. In my experience, the best and most easy to find surface to jump on is a wooden surface. It is firm and hard yet has some give so it absorbs the shock of your weight hitting the floor. A densely-woven rug will work well too. Concrete is the least desirable of all. You will not do much more than 10 minutes on concrete, trust me! Asphalt is a little better but still tough to go for 10 minutes. Proper gym mats are great but expensive. Still, if you do a lot of jumping rope, they're worth the investment.
Overall, I believe that jumping rope is the most intelligent, efficient, and effective method of cardio training. It's time saving and multi-body benefits put it head and shoulders above everything in the cardio exercise universe.