This pedal surprised me positively on areas i didn't expect but fails at what i bought it for
the build quality and user experience are both great, its very easy to grasp all the buttons and its fast to make all the adjustments you might want combined with 3 preset slots
EQ: its a simple 3band EQ with good quality not much more to say about it, what is really nice about it however is the ability to be able to turn off the bands this will help you shape your sound a lot better or can be fun for performances.
the compressor, one of the reasons i bought this pedal was because i wanted a compressor that can boost the lower level frequencies to give my guitar a more dynamic range, if your like me and looking for this look further, its more of a suppressor then a compressor it only lowers the volume of chosen band.
if you are looking for a suppressor that can duck this pedal is a good option, its also very useful to take some attack off your guitar
the controls of the compressor are very easy to understand and the lights on top of the device make it easy to see where to set your treshhold
m/side stereo imaging: it really depends on what type of sound you are working with here, when i send an ARP into the golden master it really can bring it alive and greatly improve its sound, its also great at improving stereo imaging on tracks that do not have a lot of it yet.
however the main reason i got the golden master was that i wanted to use it to clear up my ambient tracks but from my experience it makes the sound more muddy itstead of more clear when you have large stereo reverbs because the mid band range is very wide, if it had been a 4 or 5 band it would have been a lot more useful to create interesting stereo imaging.
two other things you should be aware of when using the m/side is that it will de/increase the volume a bit (easily fixed with the EQ) and if you make the high end more stereo any hiss or noise will become very noticeable.
finally one more thing, even with the compressor turned off and the EQ/stereo in middle/neutral it will still very slightly adjust your sound