I recently bought a rowing machine (Concept2, "top of the top") ... and I'm very disappointed.
It's just not challenging enough (and I'm not very fit). Running/cycling (on a machine), I can easily ramp up the difficulty enough so that I'm sweating in 10 minutes. Rowing, I barely sweat even after 20 minutes (on max hardness, 27ish strokes/minute).
One of the best "time savers" for cardio is HIIT, and you just can't do that rowing.
It's just not challenging enough (and I'm not very fit). Running/cycling (on a machine), I can easily ramp up the difficulty enough so that I'm sweating in 10 minutes. Rowing, I barely sweat even after 20 minutes (on max hardness, 27ish strokes/minute).
One of the best "time savers" for cardio is HIIT, and you just can't do that rowing.