Since Endnote 8, the 32,000 size limit was removed from endnote.
Most of us are in the Endnote forum, ummm because we use EndNote, for better or for worse.
Procite is no longer under development, although still supported. You could go over to the other two forums and pose your question. I am sure they will tell you why they prefer the programs they use. (although judging by the activity in the forums, Endnote must have a large market share, or they go elsewhere for their discussions). See Thomas’s comparison here http://www.thomsonisiresearchsoft.com/compare/ and Wikipedia has a more extensive listing of software.
http://en.wikipedia.org/wiki/Comparison_of_reference_management_software.
there is another place, but I can’t find it right now…