Yes, that is my understanding. The concurrent road bikes were rated at 19 hp, the ISDT Replicas are supposed to be low 30s hp. On a piston port two stroke you don't get something for nothing - increased power comes at the expense of decreased tractability, with a side order of drastically increased fuel consumption.
The ISDT Replicas didn't get a 5 speed box several years before the road bikes for no reason. IIRC they were also supplied with a variety of gearbox sprockets to be changed during a competition to best tune the gear ratios for the conditions - bog hopping requires different ratios to high speed trials.
I have only had the head off mine, as the cylinder won't come off with the engine in the frame (unlike the road bikes), so have not measured up the ports and piston to compare with the road bike equivalents. The exhaust pipe & "silencer" is completely different. The carb is also different - a remote float bowl type compared to the integral type fitted to the road bike. Different air filter arrangement, too, with a much larger element which IIRC is from the Trabant car.
All in all not really a practical "daily rider" or back roads exploration bike IMO.