Jason,
I'm a new owner of both the rower and the SkiErg having bought both in November; I also have had a very nice elliptical for five years, and a decent weight room at home. And a membership to my climbing gym for the last four years.
It depends on what you want to accomplish from each machine, and how often you will use them. For me, my primary motivation is to improve my climbing. I'd used climbing, strength training, and my elliptical to improve my sport, balance out my muscles (strength training), and work on my cardiovascular health (energy systems). I wear a Polar HRM to gauge calorie burn for all of these.
Observations:
* My biggest gains have come from climbing - whole body workout, I love the way it gets me outdoors, and works strength/flexibility/cardio. I'm consistently in the gym, 3-4 times a week, with a regular workout program now. I de-load every five weeks or so.
* The elliptical is better for the instant gratification of calorie burn, when I go for intense intervals. However, it hurts my feet to use it more than once a week that way - and my body gets used to the motion after several months, so even more effort is required to maintain that level of burn. Given that, it's making more sense for me to use the elliptical once weekly for a few months, and then swap it out for some other piece of cardio equipment. However, this is the only piece of cardio equipment that I can use where I can guarantee I'll be able to get to 90% HR max without hurting anything (except my feet if I do it more than weekly). A decade and a half ago my poor feet were not an issue.
* The skierg is a fantastic alternative. I can burn calories very nicely on the skierg. It does not hurt my feet. It helps build my core, it's great for my triceps - I've stopped specific tricep exercises. I feel like it helps my back, too. I use the SkiErg interspersed with 500m sets in between strength training sets - say 6x500R5 min, with "rests" meaning time for the weights. I also usually add another 3x500m session to do extra mobility work midweek. I strongly prefer intervals to longer pieces on the SkiErg because it is noisy and gets hard fast
But I love it as I'm using it now, and can easily get my HR up to 80% max. I cannot do it in good enough form to hit 90%+.
* The rower is a lot of fun. Great full body workout. The Concept 2 is a really nice machine. My biggest issue with the rower is that I really want to improve at it, and I have to hold off on using it too many times a week because recovering from rower interferes with my climbing days, unless I'm not working hard. And that's boring. Also, I cannot use the rower yet for hard interval training yet - that's a form issue on me, and one day that's going to be a solved problem. On the other hand, I can use the rower for longer slower periods (listening to a podcast for an hour) or for harder rows that get me above 80% heart rate, pushing towards 90%, half an hour. I can feel muscle endurance improving, my core, shoulders, lower back all feel better. If I weren't loving climbing I'd probably shoot for rowing. And if I weren't climbing and had to downsize, I'd probably pick the rower as my at-home cardio machine. OTOH I can burn more calories in 30 minutes on the SkiErg so it would be a hard call.
* I've had an exercise bike. I sit too much at work for this to be a good complementary option for me. But some people love it, and I used to enjoy biking for fun outdoors, before taking up climbing.
* Strength training is what builds muscle. Eating right is what takes of the weight. Someone here regularly says - "pick up heavy things" for strength … that's truth. I like weekly heavy "5 rep max" training just now, and regular mobility training interspersed.
The most important thing, though, is to see which machine does what you want in a way you enjoy, and can see yourself repeating several times a week - unless you are like me and invest in having variety at home. I'd suggest using the SkiErg in a gym, if you can arrange for a gym membership even for a month. Not everyone can stick with the SkiErg. You're not going to be able to hear most podcasts over the whoosh of the mechanism, or read a book, or watch a movie - so long slow distance may get tedious. Some people manage it. You can't read a book on the rower either, of course, but you can watch a movie if you don't mind moving closer and further away from the screen.
Stats: F 57 5'7.
RowErg PB: 500m 2:07.3; 1000m 4:44.5; 2000m 9:44.8; 5000m 23:51.6; 6000m 28:35.9; 10000 49:43.4
