On the servo city website I noticed that they seperate servos as high torque and high speed. With all things being equal like price, type gears, etc. what are the application that require speed over torque or vice versa?

Just a guess, but would 3D flying need more servo torque and precision flying more servo speed?

"high torque" and "high speed" are really not that important as terms go.

You want to make sure any servo you use has enough torque to do what you want it to do. That's critical.

You get faster and more "locked in" feeling from higher speed servos.

So, when picking servos, pick the highest speed servo you can afford that has the torque you need. (plus a bit of extra torque, just to be safe).

Generally, giant scale sport and scale planes need lots of torque, but they aren't expected to do lots of acrobatics, so slower, high torque servos are fine.

For acrobatics, you usually want faster servos for quicker response. Smaller acrobatic planes, like small 3D planes, really benifit from high speed servos.

Giant scale acrobatic planes need both high speed and high torque, so you get multiple high speed servos ganged together and so on.

Servos also have what is called "deadband", which basically is a measure of how small a stick movement they respond to. If you watch an inexpensive standard servo while very very carefully moving the stick, you can often see where you can move the stick a little and the servo doesn't move. That's the deadband. The narrower the deadband, the more accurate the servo can be.

I'd say that the scale planes, warbirds, and sport could use the torque. The aerobatic planes need the speed, especially 3D planes. You gotta get that thing to stall instantly to do good crisp transitions to 3D stuff. I prefer speed myself. Anything over 15 seconds is too slow for my flying needs. The thing is that the 3D planes really need high torque AND speed so it gets expensive. Look at the Hitech 5925, .08 seconds at 6 volts. Those are going on the tail feathers on my DPM Edge 540T 26%. Should be pretty fun.

Also note that for the same price you usually get the same servo motor and casing but with a different gear set. So you have to trade off torque for speed and visa versa. A good example of this is the 5945 (higher torque slower speed) and 5925 (lower torque and higher speed).