Thought I would post some [still relatively early] impressions between the Cyan 2 and the Merason Frerot (sans POW1 power supply) as after comparing the two in my home setup I've decided to list my Frerot for sale (there's your TLDR).
Before I go further I will say that I think the Frerot is a great little DAC and if I'm just comparing the two units by themselves (with no upsampling shenanigans involved), it's a pretty close race and would come down to preferences. I hear the Frerot as slightly wider, a bit brighter and airier (comparatively). It's a nicely detailed DAC but smooth without any sort of over-sharpened or etched sound to it. The Cyan 2, in comparison, has more weight to it. Notes feel like they have a bit more impact, and while the stage does seems to narrow in just a bit, it also extends out deeper than the Frerot. To my ears it still sounds similarly detailed, so I think it would come down to the rest of your chain and what you're looking for, but personally I prefer the weight and the deeper, holographic stage brought by the Cyan 2.
The major swaying factor for me on the Cyan 2, however, is its capability with HQPlayer as a NOS DAC with huge sample rate flexibility. I don't want to make it sound like HQPlayer is a necessity here, because the Cyan 2 is awesome by itself. But HQPlayer really takes it to the next level and opens up so many options to tweak the presentation and sound of the Cyan 2 through its various upsampling filters and the ability to run either PCM or DSD. The Frerot is really limited in this department as it is PCM only up to 24/192khz, but if you have no interest in messing around with HQPlayer it's still a great no-fuss DAC.
I know the Frerot also has a discrete power supply (the POW1) which can be added to it. I've heard various reports about what it does; some people say it's negligible, some say it enlarges the stage, some say it just tightens up details. I haven't tried it, because it's a bit over $1,000CAD to do so and it's an awkward extra box to fit into my setup.
So there it is, both great DACs but I prefer the Cyan 2 and its flexibility makes it an absolute win for me.