I got this because I wanted to have an opto compressor with a small format, mainly for compressing the lead vocals in mixes but also for mono instruments.
I particullarly enjoy the smooth character of the La2a plugins I have but wanted a hardware compressor, because they tend to sound even smoother and tend to give you more decibels of transparent gain reduction.
This thign totally blew me away, it is fast, really fast! So fast that it actually distorts on the fastest setting at high levels of gain reduction, but the distortion is brilliant.
I am currently mixing a very punky, rock track, with a very dynamically, inconsistent vocal and within seconds, I was able to even out the vocal and give it so much energy by using the fastest attack and release setting. I'm doing around 12 db of gain reduction at times and it sounds amazing and super even, yet full of life and in your face!
I also tested this on acoustic guitars and it shines at the slower settings while the fastest settings tends to distort the guitar a bit for the style of music I was working on, but again, super quick results, its super easy to emphasize the sustain of the guitars with just a few turns of the knobs.
Bare in mind like with most if not all hardware compressors, this unit starts compressing before it starts indicating it and I found for myself that staying on the VU meter for the output level tends to show me more accurately how much gain I am reducing, rather than setting the switch to GR. I find it easy to view the level before I start compressing and then notice the difference after I have applied gain reduction, and then just push the makeup gain up to reach close to unity gain.
I tested this on drums as well and was not super impressed, but I did not get it for drums anyway so I am very happy. It kind of does a 160ish trick but not exactly. It can be used at low to moderate gain reduction for percussive material but it depends so much on the tempo and style of music, so for now I will keep using other compressors for individual drums and groups.
In general, this compressor can be both fast and aggressive, kind of like an 1176, with beautiful transient response and excitement, but it can also be slow and smooth like an la2a without the added tube weight, even though it does seem to add a very nice color of its own as well.
If you are wondering if you need it, id say get it, its amazing! I was really wondering if I need yet another hardware compressor and decided to get it very spontaneously. Honestly, this thing does so much of its own thing that I cant get that character from any of the plugins or hardware I own and it is beautiful!