How much better any DAC will sound will depend on several factors. First and foremost are your ears and preferences. It'll also depend on the quality of the internal DAC in your AVR, and the overall resolution of the system. If the AVR isn't good enough to show the differences between DACs, then it won't make a difference or not enough of a difference to justify the cost.
I can't say I'd definitely hear any differences or not, as I don't know your gear.
I can't say I'd definitely hear any differences or not, as I don't know your gear.