If I did go with an extension how necessary would the cross auger clutches be?  From what I've read the turret/pivot/bracing etc is the same on all S-Series.  Ours is a S660.  Should not have a problem holding up to the extra length as they offer 26' augers from the factory?  I'd just feel better knowing that the auger was completely empty.  It works out 95% of the time to get empty but the other 5% it would be dang handy to clean the auger out.