This review has been updated after working with the fantastic Peterson support staff.

The tuner itself functions well, but the lack of articulation is a bit of a pain point

Other clip-on tuners use ball joints that can rotate freely and allow you to position the tuner to face you, the player, regardless of how you clip it.

I bought this for classical guitar, and it's difficult to adjust to face me.

Initially I didn't even know that there was a rotation point where the arm connects to the clip body. Peterson support pointed me to a video to verify that it was working, and after that I forced it to turn. There was a snapping sound as it broke free and started to rotate, but it's very stiff, so much so that the amount of torque required to rotate it while it's on my headstock actually just moves the entire clip instead.

Also, where the arm connects to the tuner only rotates like a hand on a clock. I wish it had either a ball joint here or the same type of joint where it connects to the clip to allow for better alignment.

Hopefully the replacement unit Peterson is sending me rotates more freely.

Update:

Since Peterson is sending me a replacement, I decided to see what could be done with this one.

Each articulation point is governed by a small screw. The screw on the back of the tuner body is hidden by a rubber plug. The screw connecting the arm to the clip is behind the gray rubber, and the one on the pivot point where the arm connects to the clip is exposed.

I started by accessing and loosening each one, very slightly. Only 1/16 of a turn was all it took to make them more free and possible to adjust better while on the guitar headstock.

However, as they rotated, I noticed very easy spots and more stiff spots, so I went ahead and disassembled it further, removing the screws altogether. What I found was that the plastic on plastic points were rough and had manufacturing imperfections that were causing issues with what could have been a smoother operation.

I ended up smoothing every mating surface with varying grades of micromesh, then applying a dry teflon based lubricant before reassembly.

It's now much better.