I raced the Cat2k for years and then ran the 3k for one season. I'd say the 2000 is still the better car, the only place i ever really got to grips with the 3k was at the 2000 Euro's in Sweden (Qualfied 9th) but apart from that i couldn't really get on with it.
I'd have another Cat 2000 if it came with the Alloy gearboxes front and rear, towards the end of running the Cat we had a nightmare getting the "blade" drive shafts to last so they'd have no hope nowadays