Olympica Nova III or V?

Get the V's.  Even at low leveling listening, they would be so much more enjoyable.

I have had the Vs for several years and never thought about upgrading my speakers.   Tweak your source/DAC stuff to move up the listening ladder.

Thanks for all the advice - really appreciate. I worry about the bass becoming overwhelming in the apartment. I had a pair of Sonetto G2 VIII in our previous 19.6 feet x 19.6 ft apartment living room with single volume regular height ceilings - and the bass completely overwhelmed the room. 

Would the nova V be a risk or is the Sonetto g2 tuned much deeper than the nova?

Ps. I’m using a Luxman 509z

There is never a "right" answer, given the subjectivity of individual preference. The IIIs, however, are phenomenal speakers (though the current list price of $18K does make you scratch your head). You do have to like the Sonus Faber sound, which I find quite lush and romantic.

Is the base as tight and focused as it is on the Vs? No. But with a sufficiently powered amp (you'll likely want to go ss), these are immensely musical and enjoyable speakers. You will likely be very happy in your space with the IIIs.

I've extensively listened to both speakers.  With your large size room I would lean towards the Vs.  Regardless of which speakers you choose the closeness to the front wall could be an issue.  If this causes the speakers to bloat or boom you might find that bass traps will help tremendously.  Good luck and cheers.  

"....but became grating over time.started becoming edgy, clanky, piercing, edgy and clenched sounding and this was with the prescribed amps being used in the demo..."

The above description of sound was coming from the electronics... not due to the speakers... this is not the sound any Sonus Faber speakers bring to the table... This would be the sound fed them.