DeluxeBreakfastI have both, and they sound quite different.
I actually like the SMSL Q5 Pro more. I find the Q5 Pro to sound more organic and musically enjoyable.
The TEAC AI-101DA sounds more powerful, but stiffer and not as emotionally communicative. The music just doesn't breathe or ebb and flow as much on the TEAC.
Mind you, this is with an outside source fed into the AUX input on both. So I cannot say how the DACs compare.
Build quality of the TEAC is impressive. It feels very high quality. The Q5 Pro, on the other hand, has acceptable build quality, but it is nothing to write home about.
On sound quality of the amp section, I prefer the Q5 Pro, and don't use my TEAC AI-101DA in my little secondary system currently. That may or may not be different with the DAC section in play.
This is all through a pair of CEntrance Master Class speakers.