While CanyonMan gives some good advice. There are several reasons to upgrade the Glock factory plastic sights. You might want metal, you might be shooting in low light, etc. I would advise that you do need to use your sights many times in self defense situations.
My G36 has TG-H3 sights and I love them. See the pic. I would advise to upgrade as better have and not need than need and not have. They are not that expensive and if you are carrying this gun as much as you say, well worth the investment. Pretty darn hard to take a pic with my cell, but I did.