I have one. It's a very crisp and transparent EQ that allows tons of boost without sounding EQed --- I often find myself boosting 10-15 dB without taking particular note of that ;-) The only other EQs where I boost similar amounts are the Manley Massive Passive and my Siemens w295b, both passive designs. I wouldn't call the Museq a "super clean EQ", though it *can* be super clean, as the slew rate limiting circuit that can be switched into the signal path gives it a nice subtle "vintage" type coloring.
The bottom end is very solid, the treble very smooth yet fast --- transient response on the unit is nearly scary. In a way this unit sounds like I always imagined the GML EQ would sound but never did; we have 2 (non-mastering) GMLs and I keep finding them harsh and resonant sounding (well, they're obviously great, but they are those 2% more harsh and resonant than the Museq to my ears). It's not a character box so if that's what you're looking for the Museq is not for you. It is however an EQ that can be both subtle and be used for extreme curve bending while always retaining signal integrity ...Elysia-style. It complements my Massive Passive and w295b perfectly, between the lot there really isn't much I feel I'm missing.
After all the praise, it does have a couple of bits that I think could be improved on.
First, the low shelf/filter band has a weird frequency selection --- you even get a step between 9 and 10 hertz but there's also just one between 55 and 65 as well as between 65/75 or 75/95 , the are where you'd really need more precision. All in all there are 9 steps between 9 and 30 Hertz and 9 steps between 55 and 120 Hertz.
Another thing is that while the parametric bands are wired in parallel (which makes for the excellent transient response), the high shelf is wired in series
which results in the out-of-band noise of the mid bands to be amplified when boosting the shelf. If the shelf was wired pre-BPF, this would not happen.
To put this into context: the noise is only an issue when boosting by 10-20 db on multiple bands simultaneously, so it really is NOT an issue.
But the overall rating I'd give this EQ is stil something like 6 out of 5.