All data counts, even white spaces. a file with 10 \
's is bigger than a file with none. As far as d/l time a commented character weighs just as much as one character of code, so no comment size is NOT 'negligible'.
I don't remember if comments are parsed out or simply skipped either way as they are not instructions they don't present a processing load.
That being said, and I am saying this tho I am particularly lazy and stingy with my comments, commenting your code is GOOD PRACTICE. Have you ever written a brilliant piece of elegant code and gone back to it 2 years later ? What if you have to work with a team? trust me comments are quite worth their weight.
Think about it. You could 'streamline' code and probably even type quicker by not thinking of meaningful variable names. Instead of: namesOfPeeps=new array('ray', 'veronica', 'havoc', 'bushy', 'eric', 'paul') you could simply code: a=new array('ray', 'veronica', 'havoc', 'bushy', 'eric', 'paul') and save 11 characters, plus the typing time, plus the time of coming up with a meaningful name for your variable. But trust me, in any piece of code with more than four variables this will not be worth the hours of debugging time, the difficulty it will present when revisiting and revising this code for later use , and the fact that the code will be difficult to share with colleagues.
Really if you have streamed line your code so that the only things that bares reviewing is your commenting habits , you have earned a break and probably don't need to streamline any further at all. Other wise it best to focus on real bottle necks like redundancy, inefficient functions, server requests, heck even image sizes.
some people keep a production version ( commented, formatted and easy to read) of their code and a work version (uncommented, minimized, all superfluous white space characters deleted , and completely unreadable by humans). That's an option, if you dont mind the extra logistics.