I have tried Intel's vtune with a rather large project about two years ago. It was an instrumenting profiler then and it took so long to instrument the DLL that I was attempting to profile that I eventually lost patience after an hour.
The one tool that I have had quite good success and which i would highly recommend is that of AQTime. It not only provides excellent performance profiling resources but it also doe really good memory profiling which has been of significant help to me in tracking down memory leaks.
