I agree with Bob that if you are using a typical, small sound system, you probably won't hear much (if any) difference). I am also using a Bose system - the original L1 Classic PAS with one subwoofer. After using the headphone output of my laptop for several years, I do hear some difference in sound quality. Not huge, but noticeable.

The frustration I began to experience in 2015 was that when I booted everything up, I suddenly had no output from the laptop until I disconnected the cable from the headphone output jack and then plugged it right back in. Not a huge deal once I figured it out, but annoying just the same. This did not happen until after an update in early 2015 of either Windows 7 or BIAB. I used the same computer and sound system for years and never had to do this unplugging and replugging but once the problem began, I had to do it every time. A minor irritation, for sure, but I was able to eliminate it completely by using the audio interface, and the small improvement in sound was a surprise bonus.

Jim
Psalm 33:3 Sing unto him a new song; play skillfully with a loud noise.

BIAB 2018 build 519; Dell Inspiron N4110, Windows 10 64 bit, Intel Core i3-2350m running at 2.29 GHz, Memory: 6 GB DDR3, SDRAM 1MHz