Is the restored content in the Enhanced Edition any different from the Unfinished Business mod? Is there more or less restored content in EE?

I think this forum post from the Beamdog forums answers your question:

http://forum.baldursgate.com/discussion/37272/i-have-iwd-complete-from-gog-does-iwdee-offer-enough-new-stuff-to-make-it-worthwhile

Basically, the restored content in IWDEE is almost exactly like UB, excepting the Marketh's Ring quest. I'm not sure if the item restorations and item drops that are part of the UB mod are part of IWDEE.

There's also some new content in the form of add'l items (katanas and monk gear, for example) that are relevant to the new classes and kits. There's also some minor dialogue changes to reflect some of the class and race combinations, although I didn't notice much difference (the half-orc dialog options were pretty funny, though).