We used Grouser tracks with soft rubber pads. I dont like them for several reasons.
1. Very difficult to get on the tractor and to get the slack out
2. Pads fall off when being used on concrete and dirt
3. Wheels just spin inside the tracks when getting into clay since theres really nothing to grip to
Theres also another company called McLaren that offer basically the same thing. There are also companies offering it looks like pieces of steel in a C shape with chain links and i cannot see how those are supposed to work considering it has absolutly nothing to grip to.