Originally Posted by DropShotArtist
Isn't hitting a first serve ace or unreturnable serve ALWAYS more desirable than hitting a serve that requires a follow-up volley?
Depends. Trying to hit an ace with EVERY first serve can tire you down quickly and you won't get a high % of first serves in trying to hit absolutely perfect first serves (aces) all the time (Well, maybe you can if you are Goran Ivanisevic or Richard Krajicek, but few people can do that).
A good kick first serve can make you win the point as well with an easy first volley and you will get them in with a higher % than other types of serves.
In fact, in my opinion, Rafter's or Edberg's first serves were just perfect to win easy points with first volleys, for example (and they both won more points that way than when they tried to hit aces).