if u talking the differences between 32 eccs and the nics, then there are a few:
i wouldnt know them all, but as rhino said the turbo is the biggest change.
also the eccs has a much bigger plenum with a 6 intake port head, while the nics has a 12 port head.
eccs has a bov on the pipe just b4 the tb
eccs has bigger injectors
the throttle bodies seem different - the eccs having the cable on the opposite side to the nics
also different radiator hoses and a few other minor things...
comparing the 31 nics to the 31 eccs (still red top), there are less obvious changes - the main one being the bigger plenum combined with the old 12 port head.
to answer your question, the 32 eccs is much better in regards to tuning potential. it is a better base engine to start with - and also a/m parts are much more common.