The Solaris 2020 does look very interesting, I quite like the small form factor.
I demo'd the OG Solaris sometime back and I quite liked it. The soundstage and presentation is quite unlike what I've heard in other units - very 3D, spherical and round with excellent layering and separation backed by an exciting DD bass. The only thing I did not enjoy was the stupidly big shell + poor fit. It's actually a nice compliment to the Andro (makes sense to own both as they sound rather different). Hoping the 2020 sounds the same w/ the small form factor, I'd consider that a potential buy.
Also, on another topic, it's quite odd how the ZX300 is such a good compliment to the Andro OG/S (in 4.4). While not the most technical, tonally it sounds very pleasing and adds some much needed bump in the bass + dynamics.
My main issue with Solaris (OG and 2020) is that the shell is much wider at the bottom where the sound bore is placed compared to Andromeda. Because of that, I cannot fit the IEM pointing straight to my canals compared to the smaller lower body that we get from many IEMs and Andromeda, and as such I have to angle the IEM pointing downward thus making me lose seal when I move around or when my ears get a little bit steamy. For me, I still can't consider Solaris 2020 until CA decides to make a smaller lower body that can fit my tragus and antitragus cavity without ear pain (Andromeda or any CA IEM with the same shell design as the Andromeda fits like a CIEM to my ears)