I've had three fifth wheels each one had a different style of slide mechanism. The first was the rack and pinion. Several times the bolts on the drive shaft, coming off the motor/ gear box, broke, along with bending the square drive shaft tubes. The second trailer had hydraulic slides. Two problems here. First they three slides operated sequentially, so you could not open one slide at a time! A pain when the weather was inclement and we only wanted to open the bedroom slide for an overnight stop! Also, we had a ram under the bed come loose and rotate, breaking a fitting and soaking the rug with transmission fluid. Our latest unit, a 2014 345 Open Range, as with all of the other Open Range trailers, has the cable actuated slides. So far, no problems. I agree with many posters here, each system has Its positives and negatives. At least if the cable system has a failure, everything is easily accessible for repair. I also like the weight saving aspect.
Bandaid