I'm very pleased with my MBHO 603a + KA500HN performance. They do a great job cutting out crowd noise and still gathering a full stereo signal. I don't use them very frequently, but when I have I've been more than satisfied with the results.
I can't speak to any of the other models here, however, so I'll be curious to see what others think. I'm particularly hopeful that Bean will pop into this thread as he's loves him some hypers and uses them most of the time, or at least whenever he can get away with it...