My husband likes them a lot. He used to do Krav maga and Jiu-jitsu and after injuring his knees and shoulder now takes precautions while doing crossfit to keep himself fit. He already had several knee pads but he likes this particular one more since it has soft, silicone protection on the knee that makes a huge difference during impacts. He has two other ones with protection around knee area but they feel hard more like a plastic. He liked it so much that he ordered another set to have for both knees and elbows.
It's great to have back up ones since they get dirty and need to be handwashed and air dryed. That can take a while and I wouldn't want my husband wear wet set.
Price wise I felt that the asking price is a bit high compared to other ones with same feature and considering that elbow pad does not have the same silicone padding like the knee pad I wouldn't personally go for it. But it's my opinion and your choice. My husband is savvy with it though so I am happy for him.