As a programmer who works remotely, and who lives right next door, I work from the Sahara West Library all the time! Overall, I have been pretty happy with my experiences there.
INTERNET CONNECTION: Solid.
I am a web developer and have had no problems doing what I do there.
My one gripe is that the page where you log in to their wifi is difficult to use. I've got it figured out, but as someone who designs software for a living, I am 100% sure that there are people who try to sign on, can't figure it out, and just quit and go home. I told someone at the tech desk about this, he gave some excuse that he doesn't think they'll be able to fix it, I mentioned that I'm a developer and am confident that it can be fixed, and he just brushed it off.
HOURS: They are open 10am-8pm Monday through Friday, and until 8pm on weekends. _Fantastic!_ I love that they are open on weekends, and are open late on weekdays!
NOISINESS: Ok. It's usually pretty quiet, although sometimes there will be people who are loud.
DEMOGRAPHICS: I see a big mix of people there. A bunch of families, some students, a good deal of older people.
STAFF: I actually haven't rented too many books from them, but in the few occasions I have, I have found the staff to be great! I've found them to be really knowledgeable and eager to help.
One time I had to do some weird file transfers from a USB drive to Box.com that even I as a software developer was having trouble figuring out. I asked one of the guys at the tech desk to help me and he spent about twenty minutes sitting with me until it was working.
SEATING: It can get pretty crowded there. Sometimes you'll have to walk around for a while to find a place to sit.
One gripe I have is that there aren't really enough outlets to charge your laptop/phone/whatever. Some tables have them, but many don't. Sometimes I find myself needing to charge my laptop but unable to really find a place to charge it, which is frustrating.
INDIVIDUAL STUDY ROOMS: There are a good amount of them available, although they get booked fast and are thus hard to find. One gripe I have with them is that I always find them to be too hot or too cold, and also too stuffy, so I avoid them.