I have seen issues at clients where the prep/unprep stuff was a huge perf issue because it was getting called a bajillion times for stuff that was only executed ONCE! It is ridiculous to go through the round trips and extra overhead to prep something and then tear that prep down just to make ONE call to the database!!
Best,
Kevin G. Boles
SQL Server Consultant
SQL MVP 2007-2012
TheSQLGuru on googles mail service