Choosing between 8i Standard and Enterprise?

  I'm trying to understand the difference between Oracle 8i "Standard" and "Enterprise" editions. A lot of the differences are obvious ( such as bitmap indices ) but I have a couple of questions:

  1.) A datasheet I've seen says "Online index build" is only

      available in the Enterprise edition. What does this
      feature mean? Does this affect ones ability to do
      CREATE INDEX and DROP INDEX commands while the database
      is being used?

  2.) Given identical databases and computer setups are there
      performance difference between Enterprise and Standard
      edition ( eg does Enterprise cache things any better or
      allow larger SGAs, etc ).

  3.) If one is dealing with a database that has a thousand or
      so tables in total, with the largest tables having a couple
      of million rows ( total database size of 5-10GB ) and all
      access will be via SQLNet ( OCI and ODBC) is there
      any compelling reason to use Enterprise edition vs Standard?