HDMI ARC vs. toslink optical for stereo

Does anyone have experience with tv HDMI ARC tv output? I would like to get the best stereo music and stereo movie sound from my tv to my dac, which only accepts digital coax or optical.
Will the sound quality be better usung the optical tv sound output, or the the HDMI ARC tv output, converted to optical using an inexpensive converter. Converters are available on Amazon inexpensively. Any real experience will be appreciated. 
Optical is theoretically superior in performance.

When in doubt, or when you can, use optical.

There is latency with every cable...but your job is to make it as unnoticeable as possible. As it stands, even with longer cables you probably won't hear much of a difference.

I’m interested in what happens to the signal before it becomes optical. In the HDMI ARC case, thereis a conversion to optical externally.
in the non- ARC case, the conversion is in the tv. Both methods yield optical into my dac.
Which method is more accurate?