It's important to know that the pace of garage doors would depend on the power of motors. The truth is that the best of openers will not have the door moving with incredible speed since this would be unsafe. They usually start opening with a slower pace and accelerate while they do the exact opposite when they are closing down. They start moving down fast and then slow down mainly for safety reasons. You should start worrying only when you see a tremendous difference to the way your door moves and search for the most common suspects.
Don't forget that the movement of the door is determined by hundreds of garage door parts. A slight damage with one of the hinges or brackets may change the way the door is moving completely. Rusty, missing or small sized screws could also cause problems. The cables might get loose and would probably have the door “dancing” all the way down to the floor. In some cases, they won't even let the door approach the floor. Garage door adjustment is also necessary. The door must be well-aligned and all parts must be tightened.
Slightly damaged garage door tracks could cause the door to stick or move slower. The same will happen if the moving components are not well-lubricated at least once a year. You need to lubricate the chain of the opener, the rollers, tracks and hinges. Lubrication maintenance is extremely vital for the good and smooth movement of the door and you need to make sure that oil should be dropped at the seams of each component in order to get to all parts. Remember that most garage door openers are set by industries to work at the lowest possible speed and you can really change that by adjusting the speed at the desired position.