Many years ago a customer on a single core computer had problems of heavy video stutter in my product. It was multithreaded and ran as I recall 5 threads (GUI, video decoding, 3d pipeline, device control and computation). Others did not have this problem. After investigation it turned out that said customer had hyperthreading disabled in BIOS. Enabling it fixed the problem instantly.

So "real" or not but from my experience HT does work to the benefit.