It's actually all true. But there is two ways they went, cambelt due to age, and rollers due to milage
My friend is an Opel mekanic, and they had the 1,6 and V6 head in stock for this purposes from 96 to 99. Both Ecotech engines 
When the belt snapped at high revs, they could also bend the conn.rod, and then the whole engine get replaced.
But there are sunshinestories to 
My son picked up a 2,5V6, and after he came home, I called up the previous owner, and he could tell me that the kit hadn't been changed for 9 years and 65.000 miles 
The belt was so worn, that there was almost no teath left on the belt, but the funny part was that the rollers was ok, and had no noise from the bearings.
My son was not happy becouse i didn't let him drive it before we changed it, but he is only 18, and I think that was his longest week ever 
I think a week's wait is a small price to pay in order to get a 2.5 at 18!!

Certainly beats the hell out of my 1.3 MkI Astra!!
