gnu find: \; vs +

ticklejw@MAL ~
$ find test -exec ./sleepawhile {} \; -type f -print
Sleeping for 1 second... done!
Sleeping for 1 second... done!
test/0
Sleeping for 1 second... done!
test/1
Sleeping for 1 second... done!
test/2
Sleeping for 1 second... done!
test/3
Sleeping for 1 second... done!
test/4
Sleeping for 1 second... done!
test/5
Sleeping for 1 second... done!
test/6
Sleeping for 1 second... done!
test/7
Sleeping for 1 second... done!
test/8
Sleeping for 1 second... done!
test/9

ticklejw@MAL ~
$ find test -exec ./sleepawhile {} + -type f -print
test/0
test/1
test/2
test/3
test/4
test/5
test/6
test/7
test/8
test/9
Sleeping for 1 second... done!

Here is the script 'sleepawhile':

#!/usr/bin/env sh

echo -n "Sleeping for 1 second..."
sleep 1
echo " done!"