Don't know the Insa, but Cooper STT have fantastic grip... and that's about all.
Got something like 12,000 km out of one set (on a 127"), and it chips on rough/stony roads.
On the other hand, Cooper ST/C have excellent grip, are chip resistant, and have exceptional longevity. I'm about half-thread on a set after 30,000 km (on a LC77). Best all-terrain I ever had, and several of my friends who operate tours/safaris swear by them. Very puncture-resistant too.
My vehicles spend most of their lives on untarred roads and offroad.