I have one. It is sort of an easy to control, lightweight SG soapbars with a faster neck and maybe more "musical" pick-ups.
Other than that it has what I assume to be typical PRS qualities: excellent nut, not intonation hassles, responsive volume and tone control. The body on mine is one piece mahogany, I guess it's the same for all? The fret job is good although there's a "soft spot" on the 9th fret of the G string (less sustain, not really noticeable).
I find the neck really comfortable, the strings are easy to bend and there seems to be more space between the frets than for similarly scaled guitars. Not sure how that is since it has the exact same lenght as my LP. The neck feels more crowded on my LP in a way, very strange. Maybe due to the blocky inlays vs birds.
The Mira responds very precisely to all playing changes, and although it has plenty of clarity is not an unforgiving instrument. Great balance there.
About the plasticky feel: same here but it doesn't bother me. I love how light and easy to play the guitar is, especially compared to my LP.
It's a good workhorse although a bit too pretty for that and my Mira already counts numerous scratches.
In the longer term I might switch pick-ups, or maybe not. I quite like that guitar as it is, it's a little gem.