To answer the OP, I have had the opportunity of comparing the two at home, in my system. My LP12 bits are listed in my profile, and I was going to start a thread on this, but I know how contentious it might be.
I won't go into much detail, but the Solstice was a disappointment on several counts, practical and musical included. I'm not sure what I was expecting, but at £16k, it was quite an expectation. YMMV of course, but suffice to say I'm staying where I am and the difference was not subtle.
My main interest was the Aro2 as I'm a bit of a unipivot junkie, and of course, I would have liked to have put it on the Linn, but the mechanics are completely different. I'm afraid the build quality has put me off bothering, even if it does become available as a separate arm.
I'm really not sure what Naim were trying to achieve here, but if you like and want a Clearaudio TT, then buy a Clearaudio TT, unless you want matching logos everywhere.
That having been said, I kind of grew to like the styling of the PS and phono stage, but lots of acrylic is not good for dust and scratches.