I have experience flying with Rotax 2 smokers. The power to weight ratio of any 2 cycle is undeniably appealing. They use a lot of gas and oil. The synthetic oil available now is amazing, and expensive.
Always cover exposed air filters with a plastic bag when you put the plane up for the day, they are a dust magnet and can appear clean but still be clogged. I had a 503 total power loss on the downwind just after takeoff. The engine never quit it just bogged when the throttle was opened much beyond idle. I was able to turn base just after mid field and landed uneventfully. If this had happened during the initial climb past the end of the runway..?
Never pull the power back abruptly after take off. Do it in small intervals or they can cold seize. A friend had this experience in his Mini-Max after a cruise-climb and he had one with this model of Hirth engine, but he has had many ultralights and I can't swear if this plane had a Rotax or the Hirth but the lesson is clear.
The only other forced landing I have had was in a Quicksilver. I had a prop mostly disintegrate when my helmet visor departed and went through the prop. It happened off the end of the runway, but too far to make it back. The prop pieces could have taken the tail off. Totally my fault. One of the many lessons here was use the top of the waist high wheat as the runway not the actual ground. The nose wheel caught in the first few kernels and flipped me...
My opinion is 2 stroke engines are not necessarily less reliable, but they are more fickle. Be prepared to become an expert.
