Many kendo students dread the practice of suburi. It is regularly incorporated into the pre-keiko warm up and is viewed by some as an exercise to develop stamina and strength. Even when this is not the intention, suburi is often conducted at a speed that is beyond the capabilities of many of the class members; in some cases beyond those of the individual leading the session.
It can be quite frightening to watch a group of earnest kendoka, thrashing around like demented metronomes, each in their own space and time; desperately trying to keep up with the group. It is also worrying to see carefully cultivated technique thrown away in order to go faster.
Before I rant on, let me make it clear that I actually value suburi as an important part of kendo training, but it has to be done correctly; at a speed that the slowest group member can match without compromising technique. In the same way that golfers use practice swings, suburi is a great tool to ensure that all the component parts of a strike are correct without the pressure of facing an opponent. Shoulder, elbow and hand movement; tenouchi, balance, footwork and ki-ken-tai- ichi can all be coordinated in suburi, but you have to allow the time to get it right.
Currently some of the more experienced kendo teachers will use suburi as the basis for teaching a technique. They then build on it through a progression of exercises that take it closer to its intended purpose. So for instance, the students practice a men attack as individual suburi, then put on men and kote and work with a partner on hitting from correct distance; finally trying full speed uchikomi geiko with fumikomi.
Suburi also allows you to train without an opponent and can be adapted to any waza you wish to work on. Not only can we use the standard methods of jogi buri, shomen suburi, zenshin kotae shomen suburi and choyaku suburi, but we can be more adventurous and try renzoku waza as well. If you need to practice at home and you are worried about the light fittings, then you can buy special suburi shinai, which replicate the weight of a normal shinai, but are much shorter. With enough imagination, you can just use your hands.
Of course there is no reason why suburi cannot be used to make your attack faster, but my advice is to get it right first and then make it quicker.