It doesnt matter the game, I always wait for action to be on me before I peek at my hole cards for 2 reasons:
1-Your cards arent going to change, so why rush?
2-You might miss information your opponents give off if you're busy looking down at your cards.
For games like stud and razz, there is another reason:
3-If you're busy looking down at your 2 hole cards, you might miss the up cards that are being folded. And its very important that you see what up cards have been dealt becase those potentially can be your outs. You might find yourself drawing to far less outs than you think because you didnt notice the other players who folded them.
You can always determine the course of action, when it gets to you. In fact, I think its better that you wait then predetermining your action because the action of those before you is what ultimately makes your decision.
So, just wait and watch the other players. In the seconds it takes you to look down at your cards and factor in what you hold, you can be missing out on so much information. And also, you're giving out viable information to other players who are paying attention.
Oh, to add-dont think you're holding up a game if it takes you a few seconds or a few minutes for you too act. Make your decisions wisely. Unless it takes you an hour or so, then it shouldnt be a problem.