"Fast" and "Offensive" are terms that go hand in hand in our game (and in most games I guess), as is "Slow" with "Defensive". However, I will concede that they are not synonymous.
My conception of it (debate expected...):
- In an offensive game, you try to make your strokes hard for the opponent to return. You are looking for winners, primarily.
- In a defensive game you try to deliver balls that will be hard to turn into winners. Errors from the opponent wins the point, either directly by a miss, or indirectly by a weak return that you can kill.
Mostly, offensive strokes are fast and defensive strokes are slow. Some exceptions:
- A drop shot is a slow offensive stroke. With a drop shot you look to win the point directly.
If the other player reaches it, there is a good possibility that he can smack it back or place his return out of reach, so it's not a "safe" defensive stroke. - A passive block is a fast defensive stroke.
You count on a speedy return to give the opponent little time to prepare a strong attack.
For a good game, your tactics need to make both offensive and defensive considerations, regardless of which is your main strategy.
IOW, offensive vs defensive is more about mindset than it is about speed, and also that choice of equipment speed should be based on the player's ability (level), at least as much as on the chosen strategy.