I've used them on one of our sm102 640 perfectors, with a max speed of only 13iph they do help make up some time. The press is fairly new with a feeder plus from the XL on it. Setting the blankets to be hit quick wash every 10,000 sheets, and timing the feeder and delivery so they are dropping at different times you can produce a lot of work. In one 12 hour shift using the nonstop feed/delivery we were able to run 140,000m sheets. Granted that was a "perfect" day but still they can be used. 95,000 sheets in 8 hours was fairly easy to do with the right stock. It does take some practice but they can and do work.
It's interesting when I was the Lead pressman(still am at heart) I would use the continuous feed/delivery all the time and everyone said I was "working to hard". Now my role has changed into Pressroom Manager and we have incentive programs where the Pressman are reviewed and compensated based on their through put. Now all the sudden the continuous feeder and delivery are being used all the time. Interesting how that works...
Mike