I've had some mixed experiences with Firestones, but I've found that the longer you are a customer (per location), the better service you will get. I bought my tires from them about a year ago and recently had to return due to getting a nail in my tire. BOO :(
I called ahead and they said just bring it by, no need for an appointment. When you buy your tires from them, they will do all repairs and check air pressure for free.
I have a bad habit with getting flats (4 in the last year), so they know me now and no longer try to sell me extra services like other locations I've been to. This is something I'm super sensitive to being a woman and honestly not knowing much about cars. I also consulted with my boyfriend before buying my last pair of tires and apparently I made a good choice because they always compliment me on my tires now, haha!
Being that this location is close to work (~5min), it's pretty convenient. I just wish they would offer a shuttle service. But at least the lightrail is coming, which will help with that immensely.