If Saint Augustine neighborhoods resemble Key West somewhat, then St. George Street is kind of "cleaner" Duval Street. A prime tourist walk, the street are lined with shops and restaurants. Some of those are quite good and some more commercial and cheesy.
I would definitely take some time to see it, but, what I wouldn't do is drive here. Either stay at a local bed and breakfast--many look beautiful and are just a block or two away from the area or get public transportation (shuttle, taxi, etc.). During tourist season, there is little parking and traffic can be congested and frustrating. If you walk, you will enjoy yourself.
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