Hey man, I have the Galaxy s4 and a mac, which is causing me some difficulties (even after your method). I was using Samsung Kies at one point, and had one successful sync of all my music and I was like "WOO! This is a good program," (because I used Double Twist before that which didn't work at all). However, now my galaxy doesn't seem to show the "USB Connected: Enable File Share" icon that Android phones typically show when connected to a computer.
I followed your instructions, uninstalled Kies and then installed android file share, but my Galaxy still won't give any signs of connection to my mac. I have checked through every setting on my phone like 10 times just to make sure I didn't have like file sharing disabled or something, but I couldn't find anything. I really hope you understand my problem and please try to respond to this with whatever help/advice you may have. Thanks.