I've had the Core since its release, and Overall, I'm fairly satisfied with what it provides. Its main features, the contact tuner and metronome, are very easy to understand with its simple and effective UI. I also like the customization with the LEDs and vibration strength, which tailors to my needs. However, there are a few things that aren't perfect. When it comes to pairing with my Android phone, the Core will constantly disconnect itself without reason, when it didn't do that on my old iPhone. Additionally, I wish that I could control my media players from my Core, as it'd be nice for either casual music listening or for practice. Lastly (and this isn't about the Core itself, but rather the tuner mounts), I wish that there as a clip-on tuner mount available. As an electric bass player, sticking a magnetic mount on my bass isn't a big deal, but as violin player, I don't really want to have something like a tuner mount stuck to any part of my violin that might cause damage were I to remove it. Overall, the quality of the Core is great, but I'm also a bit disappointed it doesn't have more.