Buy this if you're doing MIDI sync!
I was skeptical this would be useful, but I was wrong. My band has 3 computers that need to be MIDI synced so our LFOs and arpeggiators don't sound like chaos and we used to spend an hour every practice trying to get everyone synced via multiple midi interfaces, daisy-chainging, even WiFi. We started just hitting play at the same time every song.
No more! We just plug in and everyone is in sync.