I recommend that you consider only running using the following parameters instead of 'ALL'.
DBCC FREESYSTEMCACHE('SQL Plans')
SQL Plans will clear your ad-hoc bloat, and unless your server is configured for ad-hoc queries, this will help performance a lot.
If you are running SQL 2005 sp2 or older, then TokenAndPermUserStore will clear out a lot of memory consumed by the security cache for creation of objects within tempdb.
Using ALL will introduce some performance hiccups until the plans that should be used repeatedly are re-cached.
Saint Louis, MO