Okay One question at a time.
1. Power pack is an aux. motor/hyd unit mounted on the back of a excavator dedicated to run only the head, the excavator motor runs just the excavator. Great mulching power at double the fuel burn. Yesterday here in GA highway diesel 3.92, not a very effecient way to mulch. Denis Cimaf heads are designed to run off existing hyd power and do so without excessive overheating. Simply a more efficent design!
2. We have a new model in testing just for the 8 ton class and up excavator such as the Kubota 080. It is currently being tested on that unit. Reports and pictures soon to come. No power packs needed and we can mulch with the best of them.
3. Barko makes a BAD tractor! If you would like to see the most productive mulching monster made put one of our heads on that barko and get out of the way. I hope to have one mounted on a Prentice 2864 soon and can give feedback. 100" cutting width, twin hyd motors, 85 GPM @ about 5000psi. I have seen one of these units personally mulch 3 12" hardwoods at once and not bog down, that was impressive.
4. Iron horse, I would absolutely recommend putting a mulching head on your excavator. It would make excellent use of the excavator and I'm posititve you would be pleased if you ran a Cimaf head on it. We make heads for every imcrement of excavator form 8 ton and up. We size the head for your tractor and send a tech to put it into service to tune the head to your tractor! If your mulching the tree from the top down you do not need to pull it up or cut into sections. PM me your address and we'll send you a packet and you can see for yourself.