Chrome is an awesome browser and I would never seriously consider moving to another at this time.

However, removing the plus sign and keeping the button made me think there was something wrong with my browser installation and that perhaps the missing icon would be indicative of larger problems. It wasn't until I used another machine and saw the same behavior that I realized this was intentional.

Whether the icon is there or not isn't a big deal to me, but this is such a non-standard UI choice that, to users, it appears to be the symptom of a problem.

Great browser, now that I know, it's not a problem...just a curious UI choice.