I think there are two different perspectives one can have on restaurants: local and tourist/traveler.
When you ask a local for his suggestion on where to eat, you expect he is going to suggest a place he goes to all the time. So, if someone asks me where to get a good crabcake in Baltimore, I will tell them Faidley’s. I’ve been to Faidley’s a lot of times, and I think that the person asking for my opinion is expecting that my recomendation is not based on the one and only crab cake I had at Faidley’s five years ago.
Now, I’ve only been to New Orleans twice, but if someone in my office ask me where to eat in New Orleans, I’m going to suggest some places I’ve only been to once, like Pascal Manale. I’m offering my opinion as a tourist/traveler, which is based on limited exposure to the restaurant. I’m more or less saying, when I visited New Orleans, I had a really good meal at Pascal. If that person comes back to me after his trip and says he didn’t have a good meal at Pascal, I’m not going to be shocked. After all, I only had one meal there. But, if someone says they had a bad crabcake at Faidley’s, I would think it must be a freak occurence or that person doesn’t really like crabcakes to begin with.