I agree with the view. If the Global Temp table us not used in multiple sessions, we should use the local temp tables only. Even it is advisable to use the local temp table or derived table "Table" variable instead of Global temp tables.

It will always take time when you want to drop a table as it will check the validy of your statement and any reference made to the object. In case of Global temp table, the scope of validate increases and hence the time taken to validate.

Try to avoid the usage of Global Temp table whever possible.

Refer to http://www.sqlservercentral.com/articles/Basic+Querying/temptablesinsqlserver/1279/ for more information.