I bought the Sonic Research ST-200 based on posts here and a Korg TM 50 tuner metronome. I haven't been thrilled with either. I recently got a Peterson Strobo Plus HD and added the metronome function for $30. I'm very happy with the accuracy, display, and ease of use of the Strobo Plus. While it's bigger than the SR and the Korg, it's worth it by being more useful.