Joe & UG vs. UG DE...
Hey Joe.
Depending on the age (serial number) in production, the gears were changed for the transmission/motor. This was done to help reduce, minimize or eliminate skipping or hopping on some of the carpets; especially if the carpet(s) are real 'grainy' in design.
The motor exhaust vent was modified to change the air path upward, thus reducing blowing of debris on bare floors.
The delicate/normal switch, (which you mentioned already), & this thus gives you four (4) speeds in conjuction with the regular safety switch. The amperage & wattage specifications did also change slightly.
Most of the rest of the changes were cosmetic &/or had already been incorporated into the late productions of the 'plain' Ultimate G model.
I hope this helps you Joe. (And yes, that is a pretty good deal, unless you hold-out & get lucky with a better deal. ~~lol~~) My opinion, you'd be hard pressed to find a better performing, quality built machine, 'presently' on the market.
Cheers & hagd all,
Bill