There are of course several up-sides to it, but there are also quite a few downsides to it.
Let me just clarify what kind of memory I actually have.
I can vividly recall sight and sounds, into the tiniest detail. Without even concentrating, I can visualize people I have seen for even just 5 minutes. I can even recall such small details as jewelry, hairstyle, make-up, etc. Out of the approximately 80 persons I meet regularly (at least once a week), I can recall eye-color, maybe around five different sets of clothing each have worn, jewelry, tattoos.
I can picture people, myself, and even whole scenes in fine detail, walk through them, look at them from bird-perspective. Even the schoolyard from first grade, which was 13 years ago for me.
I can also "listen" to a song I have heard, by memory only. I can only "listen" to one instrument at a time. It is kind of hard to explain.
Sounds great, right?
Well, the downsides are many, actually.
Sometimes, I can't control when I visualize memories. The first notes of a song, with which I have attached a memory, can trigger a full visualization.
I sometimes tend to visualize the equations and formulas my math teacher present in class, in real time. That can easily make me want to visualize the equations with various different combinations, and therefore render me much less active in lessons.
I can remember a lot of joyful experiences with my family, that they can't remember. It hurt me quite a bit the first time.
Then the most creepy/cute/whatever-you-
Only a few of my friends know that I have this kind of memory, and they all ask me the classic: Why aren't you getting A grades all the time, in everything?
The simple answer is that the "photographs" in my memory are so fragmented and so cluttered that it consumes a whole lot of my energy just to visualize one chosen memory.
More questions on human memory: