Streamlined vs Sandbox

In all my time of running and preparing games I have always thought of the game as being a sandbox. I've always let players run where they want and had a couple different scenarios ready to go depending on where they went. All having to do with some of the lore I had developed within the world.

Recently however I have began to finally come to my senses and realize it would be much easier on me to begin to run a more structured or streamlined adventure. Not something that I would railroad, but rather an adventure that I have carefully crafted and set up specifically for them to run through from beginning to end.

But, do I really want to run a game that way? Honestly, I will probably always prefer sandbox simply because it really gives players the freedom to do whatever they want. I guess it's a nice challenge for me, as a DM, to figure stuff out on the fly. I'd guess that a sandbox game would be the ideal way to run a session, at least in my opinion. But if you are low on time or are not good under pressure a pre-made adventure might be what you need.

This sudden realization came after Joseph Bloch over at Greyhawk Grognard posed the question of how to run a non-sandbox wilderness adventure. So, I guess I'm not too alone in the way I try and prepare things. With school now taking up more time than I would like, I will probably have to begin falling back on more streamlined adventures. It's not ideal, but I have to be realistic and keep the players in mind as well.

How do you prefer to run your games?