@rach_fan
nice you are getting a codex to try... people can spew all they want about which is better, bottom line you need to find out for yourself in your system, as both sound good, just different presentation
that been said, a few points to you
- you need a good optical connection in (unless you are running usb) for the codex - get a real glass cable, makes a difference
- use the codex balanced outs... it sounds substantially better thru its xlr outs compared to the rca outs
- best to run in dac mode (disable the internal volume control)
bottom line, for me, i had a gumby and sold it, kept the codex... but that is in my system, to my ears - codex provided a more saturated, rich sound, which i value
also the goofy internal relay clicking between tracks that the gumby does bothered me
have fun, good luck