I mainly bought it for the sustain. What I immediately noticed is the dynamic it gives as soon as it's activated. It "turbocharges" the sound like stepping on the gas abruptly. (Especially if you have the level set above halfway) It does what it promises. I personally set the compression (Attack) to the minimum to have more control in my hands, because it cuts quite a bit (especially the highs) and I think it works better that way. The ability to also play with the tone is very important and it greatly enhances the sound. On the other hand, the sustain is amazing. If you set it to "and a quarter", the note can sound... endless! Amazing!

As for the downsides, the noise is a problem. It behaves like a distortion pedal when activated, especially if the level is set above halfway. It adds a lot of noise. In combination with the also (slightly) noisy Boss GE7 Equalizer that I also have on my pedalboard, it made my life difficult to the point where I was considering looking for another compressor. However, I decided to buy the Boss NS2 - Noise Suppressor and all the problems were solved! I put all the noisy pedals in the loop that the Noise Suppressor has and the noise really disappeared! The collaboration between the Compressor Sustainer and the Noise Suppressor is amazing!

With a little effort, of course, and keeping the level low, you can cut out a lot of noise without using a noise gate, but as I said, if there's the possibility of using the Noise Suppressor, I consider it the best combination.

I'm giving it 4 stars only because of the noise, otherwise I would give it 5 stars because the pedal really does what it promises.

I prefer it more than systems with an integrated Sustainer pickup (ask a good guitar maker and not a seller), because it has less intense sustain (emphasis on quality and not exaggeration). However, if you want to get excited about a sustainer, buy a guitar with a special built-in pickup.

Pedal! It collects a lot of sound and gives a lot of sustain, it takes a little time to find the sweet spot. As negatives, I would say that it sacrifices a bit of the dynamic of the sound and adds a lot of noise, so you will also need a noise reducer. I have combined it with the boss noise suppressor and have created a relatively good sound.