Solving high page load time using SQL Profiler
When you run DBCC DROPCLEANBUFFERS, DBCC FLUSHPROCINDB you require that the data is loaded into RAM and all plans are recompiled. 

In a live system, you'd only this double whammy on startup or after heavy maintenance that evicted all data from cache and all plans were invalidated by a statistics update.

Your typical response time would be for the 2nd and subsequent calls.

On a really "cold" system your app in IIS would be unloaded too and would incur a CLR compile overhead