The were basically a 125 on steroids.
Set up correctly they went really well.
There were a few in Australia , my buddy had a175 in 83 and i had the 83 XC250. The 175 was better in the tight stuff but the around the 250 was significantly quicker.
Not sure about the 82 ISDE , but Cater , Boag or GB would know what bikes some of Aussie team used and what happened.