It's OK
I got the Medium version of this and it works pretty well from a resistance standpoint. It definitely provides some resistance and works well to exercise your hand or fingers. I recently had trigger finger surgery and have been told that I need to move my fingers a lot to help with the rehab. This putty works as well as the other resistance devices I have so I'm happy with it from that standpoint. It offers plenty of resistance so I don't know that I could handle the Firm version of this. It doesn't have a discernable odor but it is a bit oily feeling while you're using it. However, after I put it away I don't feel like I have to wipe anything off my hands so I guess whatever the oily feeling is absorbs well.
Rating: 4 stars