There are so many combinations of hardware/software/features in streaming/DAC components these days that picking the right one is all about understanding your requirements, mapping the options, and understanding the relative value/performance.
I have one of these units and like it a lot. I use it as a Roon streamer in my Living Room feeding a Marantz AVR. The combination of a no fuss certified RAAT implementation, solid DAC performance, and a high WAF factor makes for good value (note - I got mine over Christmas for $800 using a general 10% ebay coupon). I use the DSP room correction on my Marantz, so that's not a feature that I really need and having a single box solution with good fit/finish and fairly bullet proof operation was important in that setting.......hence good value
In my office, I run a RPi streamer feeding a D90 to perform a similar function. For that room (where value/performance are the main drivers), I didn't consider the Mini-i and I am happy that I took a different approach.
A few other comments.....
Streaming support: RAAT, Bluetooth and Airplay are implemented via firmware and seems to be very solid. The Mini does not use/support the Matrix Player software (used in the element series) that has a lot of additional features....and also seems to have a lot of bugs.
Matrix originally made comments that they would consider support for Spotify Connect across their entire streaming product line. Of late, they have said that its doubtful that it will be added to the Mini-i 3 due to the lack of processing power in the box (see Matrix Audio support forum). Note that there is always Airplay or Bluetooth as an option for Spotify streaming.