After I use recovery discs or a recovery partition to get a computer back to its original configuration the very first thing I do before going online with it... is turn off all auto-updating. Then I go through and remove all of the bloatware that came installed by the manufacturer. In the good old days it was primarily users who were the ones responsible for installing crap that slowed down their machines... these days the manufacturers and software companies do it for us.
Unfortunately I see no way to keep these IOS "upgrades" from being pushed onto the ipad nor can I figure out how to delete this 2.5 gig file withouot installinlg it. So, if you don't want to upgrade you essentially lose a major portion of your hard drive to this massive file you don't intend to install.