Let's talk real quick about what a First Look is. Basically, it's a few minutes where the people getting married see each other privately after they are all dressed for the wedding but before the ceremony.
There seems to be quite a divide among wedding couples. Either they are quite against the idea of a first look, aiming for a traditional wedding day or they are for the first look and understand it's benefits and drawbacks.
Take a look at some of the drawbacks.
I think the biggest drawback that most people are aware of, is that when you will have already seen each other. I know it seems obvious but if you've been careful about keeping your look for the big day a secret it would feel sort of lackluster if you have that moment before the ceremony.
Some people that have a first look won't be as careful about your guests seeing you before the ceremony. For some, that's perfectly fine. Especially for a small wedding, you probably won't get caught chatting with Aunt Sue and end up running behind.
Some of the benefits, in my experience.
Since you're seeing each other before the ceremony there's little reason to wait to photograph your families and wedding party after the ceremony. This allows you more flexibility in your timeline.
The nerves (anxiety, anyone?) you might be having about standing in front of scores of people can be soothed a little bit because you'll get a refreshed feeling that you and your love are in this together and have had a few moments to help each other out.
Some couples take the opportunity to read their intimate vows to each other instead of in a more public forum.
I hope that helps you see the pros and cons on a first look to help you better decide what's best for you!