Having now had our full wall slide by Schwintek rebuilt 4 time I can speak from experience. The early models of the mechanism were terrible for sure. However, the latest remake of the mechanism seems to be reliable and I no longer fear the opening/closing process.
We just finished a 10,000 mile trip and used the slide repeatedly without incident. Our slide has been successfully cycled in/out about 100 times now. The new mechanism was installed by the factory, was well done, and is far more robust (newly designed motors and completely new rack Assy) and deals with all the previous problems very well. I know more about the old/new Schwintek mechanisms than I ever wanted to know. However, to be fair, I would now buy a RV with the new mechanism without fear.