Audio can often make or break your vlog. I find the GoPro internal mic like most small camera mics to be hit or miss. Ensure you get more consistent audio with a dedicated microphone.
I might have said skip this mic adapter and opt for the one for the Osmo, but at this time it’s not out yet. Weather you make the Osmo or your GoPro your go to vlogging rig, you’re going to want to get a mic adapter.