Yes, the Beatnik seems to be a pretty useful practicing tool. Although, I think it's very important to be able to analyze accuracy just by listening. And equally important, to be able to play patterns that aren't really accurate, but still swings. Like all these Latin rhythms, for example.
In fact, some time ago I had an idea of designing a device similiar to the Beatnik, when I heard of the Drumometer (I'm an electronics engineer). Unfortunately for me, months later I read about the Beatnik in Modern Drummer

BTW, does anyone know the accuracy of the Beatnik itself? Does it measure milliseconds, microseconds or....?