Helping the cue ball roll
It is a common myth that top spins a ball forward faster than it can roll. The best a player can do by striking very high on the cue ball is to get the cue ball rolling almost instantaneously. If the cue ball is not struck high enough, the cue ball will skid for a while before it starts rolling and this will be more noticeable on fine or new cloths because there is so little friction.
Top for long losers
On certain tables that are very responsive, it is essential that top is used for long losers. If the cue ball even has the slightest amount of skid on it, the loser will go wide, probably resulting in a missed shot.