TV audio into DAC via eARC or better

My system is setup like yours.  I run ARC from the TV into my HifiRose streaming DAC or Classe preamp and it works well but there are many times where it doesn’t get the “handshake “ and I need to switch sources and then it works.  Optical is more reliable than ARC, but in some rare instances ARC is capable of better resolution.  I would be willing to bet though that the resolution between the two is identical most of the time.  You may run into audio sync issues and again, that’s a power on/off and/or switch sources remedy to fix it.  

I have two systems, predicated on room layout.  My best system has my TV centered between my two channel audio.  So I run optical into my Tambaqui DAC with quality electronics and speakers .  It sounds amazing.

Upstairs my TV is not between my speakers.  So I use a small Marantz AV receiver into a nice unpowered sound bar with Left, Center and Right speakers.  This is connected by ARC over HDMI.  While the convenience of the usual handshake (works about 75% of the time) is nice, in no way does this sound anywhere as good as TV audio over optical into a high end system, regardless of center channel or not.

I would always choose the best equipment first, and not go with (Sonos) just to use eARC.

yeah not using SONOS just know it's very popular.  Probably going into a new DAC in the $10k-$15k range.  Maybe MSB Discrete 

The Toslink cable makes a big difference. Buy a glass one, they sound much better than plastic ones.