Plenty of differences -- some change the acidity or the alkalinity of the mixture. Others can add "notes" to the nose or exhale. Some can make the mixture more palatable (soft or smooth), others can make it more acidic or sour.
Can you go into more detail?
Missed this comment completely (mobile browsing 99%). Sorry about that.
What part needs more detail? Palatability and flavor associations with both acids and pH are a very, very complex theory. In fact, flavor engineers still don't have any proof. Some think part of it has to do with anions (H+), some think it's pH, some think it's salt (chemical salt, not just table salt).
Personally, I think they're all right and all wrong, but there IS something magical that happens with flavoring when you dick with either anions, pH, and/or salt. In food, in drink, and even in vape!
Basicaly if the flavor is tooo sweet hit it with some malic acid. If its no sweet enough hit it with some super sweet. but certain flavors I use like if I make a all fruit batch and its way over the top sweet ill add a drop or 2 of cappuccino or a coffee flavor to snooth everything out.
Also doing fruits and want to give it a more eathy taste ill hit it with a few drops of Tea notes.