Last week I dl 6.2SP2 and went to it from 6.2SP1.  It was much bigger ofc (complete version).  Well, installing new one is actually update if you have one running (make ds db backup, stop app and ds services and install ds and then app - installation figures out it already has DPA on the system and does update nicely).  Of course, if you have earlier version, different approach might be in place and those are documented.

It's kind of silly UI behavior on the downloads section (IMO), but you have to expand the "Full Release" menu entry.

Under there I found every flavor of OS supported and they all had listed normal sized files.