Not an audiophile expert by any means, but I can definitely hear the difference between the TC44C and the Apple 3.5mm dongle.
TC44C is more resolving / better detail than the Apple dongle.
Comparing the xDSD Gryphon from TC44C, the Gryphon has even more detail and better soundstage than the TC44C. In the end, we're comparing a $120 product vs a $600 product in the Gryphon.
I am currently using the TC44C when going out on short walks with my dog. Benefits of TC44C is that it does not run warm, has a small footprint, and uses less power compared to other small portable dac/amps.
I paired the TC44C with the 7Hz Timeless and I've been enjoying it immensely. Here are some reviews of the TC44C I found that gives a much better overview.
https://everydaylistening.net/2022/04/21/ddhifi-tc44c-review-perfectly-broody/
https://www.headfonia.com/ddhifi-tc44c-review/3/
https://www.ixbt.com/live/digs/obzor-ddhifi-tc44c-maksimalno-effektnyy-mobilnyy-cap.html (use google translate, a good review imo)
https://primeaudio.org/ddhifi-tc44c-dac-review/
https://majorhifi.com/ddhifi-tc44c-review/