Cooper Discoverer STT update

After a query to Cooper distributors as to cuts and lug chips appearing on my tyres I received the following reply(edited)

1) STT Super Traction Tyre isn't as I am aware a soft compound, Designed with a solid block and no sipeing its design is for traction some chipping will occur.

2) Knowing the harshness of terrain out past Peterborough tyres take extreme punishment in those hot conditions. Depending on how much 4wd driving you are doing we need to establish whether the STT is the right choice for your driving needs,Based on % of driving.

3) Tyre pressures that we would recommend .
Sand driving including soft sand between 18-20 psi.
Gravel / shale driving between 26-28 psi
Bitumen roads between 32-34 psi
*Tyre pressures need to be set against the vehicles carrying weight.
NOTE * Always check tyre pressures when cold.

Cooper tyres recently have developed the ST-C cut and chip resistant tyre which is a 90%better chip resistant and 40% tear resistant. The Sure Trac tyre may well suit your off road driving with a lot less chip and tearing lugs.The ST-C is a good 60% bitumen 40% dirt & mud.

After inspection of your STT's which shows minimal signs of chipping and cuts between blocks, I wish to advise that this is quite normal.

I am happy with that response.
Now I will see how they perform. As I interchange them with my Kelly's they will probably last me some years.