The "Double Fork" units are simply an attachment which mounts on a "Conventional" forklift. I don't have to many concerns with these units (attachments) if used in an acceptable mannner and facility. They do pose a problem when space is a concern and we found them to often be difficult when loading trailers. Often the side by side pallets are too wide when removing from a trailer and the loads will hit, get stuck on the bay door seals (weather stripping cushions). Another concern is the use of these double wides for the lack of any other term when removing or stacking pallets on racks. They have their benefits, I guess, but again when forklift traffic, pedestrians and the activity vs allowed material storage, shipment space is a constant risk - battle; the introduction of newer, different, units is not the answer. Sorry for the leangth of the response, it is just I am not sold on either the "Double Stack" or "Flexi" at this time. I am open for consideration and if proven useful can change my mind.