I wouldn't say overkill. Read what Buzzman has to say about the improvement in SQ:
DRZ/Bit One Optical Update -
A prior post asked whether anyone using the Clarion DRZ9255 and the Bit One noticed any differences between the analog and optical ouput operations. I responded that I detected no differences. Well, I was wrong, and here is an update:
I just realized that in order to hear the digital signal coming from the source, I needed to press the knob on the DRC to select the "optical" input, and not "master". That's what I get for not reading the manual closely. So, I now have to modify my original assessment of the analog vs. optical digital performance of the DRZ/Bit One combo. There is a difference, though not dramatic. I found that the optical option has what I would call a "blacker" background, with less grain. Not quieter in a noise sense, but the background now allows the music be more rounded, with less apparent distortion. It's most noticeable on dynamic passages, where voice and instrumental crescendos don't have as much "bite" or "edge" to them. They are smoother, and still dynamic. I also find the bass to have just a tad more weight, which has the effect of adding a bit more body to the midrange. The placement of voices and instruments is a bit for focused. The sound stage also appears to be raised a bit. For my listening, I will continue to use the optical option. If you already have spent $ on the optical cabling for the DRZ, I now say, use it. If you haven't, the difference isn't dramatic enough to warrant the expenditure of time and $ on the cable, modification and install unless you really want that extra 10% - 15% improvement. The analog output stage of the DRZ is that good.