I bought this for a different rower and it definitely makes a difference for me because I'm on the thin side and though I have a butt, I'm still kinda boney. The seat I have is similar in size to the Concept 2 and the grippy material keeps the cushion in place. The thickness makes me sit higher than intended but that doesn't bother me at all. Honestly, I really don't even notice the addition once I get rowing. I care that I'm able to use the rower for longer periods with the cushion and that's the most important thing to me. It gets a thumbs up from this gal!

My bottom used to hurt so much that I hated to stand up after my workout. Now with this pad I can row for an hour with minimal pain to my posterior. It doesn't slip and slide. It grip my rowing seat firmly with no straps, buckles or other devices. It is easy to clean (I dropped it on the floor grip side down and collected dirt on it). I tossed it under running water, wiped it off with a dry towel and went proceeded to my workout without interruption. For the price I am impressed.

My skin is very sensitive and I developed severe hyperpigmentation on my bottom from using a rowing machine. This pad has been a godsend. I use it on a Concept 2 rower at the gym and the non-slip bottom really works--no slipping at all, no matter how aggressively I row. When I initially sit on it, I'm on top of the pad, but then my butt sinks down into it (in a good way), so it's still supportive but it didn't throw off my rowing angle. It really does "take the edge off" the beating your backside can take if you plan to row for 30 minutes or more.

I bought this because I row longer distance endurance pieces (>10k meters) and needed a seat pad to keep my butt from falling asleep. This is definitely the thickest pad I have tried and it does offer a lot of support but the design led to another problem. The front of the seat under my legs doesn't compress the way the section under my tailbone does and that led to cutting off circulation in my legs. Luckily I saw another review for a different seat pad where someone had taken the cover off and used a serrated knife to slice off some of the foam to create an angled front. I just did this with my pad and it made a world of difference. I am also adding a zipper to the seat cover where I cut it to get the pad out and that will give my the ability to also wash the cover. With the modifications it seems like it will work out really well but without it I just swapped one problem for another. For the price, this should come ready to go and hopefully Hornet makes these changes as standard part of their seat pad.

Update (10/2)
I've now rowed over 100k meters since making the changes and it is SOOO much better. I really like it and the angled front completely solved the issue of cutting into my legs. I'm working my way up to marathon distances and found the zipper created even more versatility. I folded up a section of small bubble wrap and put that on top of the pad inside of the case and that made it even more comfortable when rowing for more than an hour. Putting it inside of the case means the bubble wrap doesn't move around at all. If you're willing do a a little bit of work on this seat pad, with a few easy modifications it can be great.

Have the Concept2 rower and greatly enjoy it but any rowing over 20 minutes made my tailbone quite sore. After 35 minutes, my left leg would start to go numb. Quite hard to row with one leg. I gave it several weeks and I just never adjusted. I even switched to intervals so I could stand up during the rest interval to get blood flowing again. Not ideal but was better than the alternative.

In comes the Hornet Watersports Memory Foam Cushion. I researched quite a few of these. Wasn't sure if I wanted straps, how thick, etc. Turns out, this one is perfect for me. It's a couple inches thick and has no straps. No straps are needed -- it sits on the seat and even when I'm giving 'er, there is zero movement.

It does cause you to sit up an inch or two higher which changes the dynamic a little. I played around with the foot straps to get in the correct position. I think I'm good with that -- legs feel like rubber after a decent row so that seems I'm doing something right.

The most important thing though, is that it allows me to row longer. I can easily go 40+ minutes now without any of the pain or numbness I had before. I've been using it for a few weeks now, a few times a week. It has compressed a little but not enough to matter. It still provides the same protection/comfort. I'm really glad I purchased this. Well worth the price -- which, at first, seems steep for a cushion. For what it provides, I'm willing to pay.