Soprano saxophones are now available in a variety of configurations. They may be had straight, straight with removable straight and curved necks, and fully curved (like tiny altos).
Adolphe Sax's original sopranos were straight. Larger saxes were curved and looped to enable the players to reach the keys and to allow the instrument to be carried. Many fine soprano saxophones are now available in this original shape.
A curved neck allows the soprano sax to be held closer to the body, more at the angle the clarinet is held. This is more comfortable, allows use of a neck-strap, and keeps the bell from hitting the music stand. Most soprano saxes with removable necks are equipped with both straight and curved necks. Some players prefer the straight neck for playing jazz while standing. This allows the bell to be aimed at the audience. The curved neck aims the sound down at the floor, and is preferred by many players for saxophone quartet or classical playing. I have noticed no difference in response between the two types of necks, only a difference in tone quality due to the angle of projection.
The straight soprano sax, like the clarinet, is more difficult to mic in a commercial setting, requiring two microphones. Micing is accomplished by placing one mic near the bell facing up and a second mic over the left hand. This allows for very little movement by the player. There are several "clip-on" double mic setups available to remedy this problem.
Curved soprano saxes, popular in the 1920's and '30's, are once again available. Contrary to popular belief, curved sopranos do not have any different intonation tendencies than straight sopranos, nor are they stuffier in the low notes. The tone is different due to the more forward projection from the bell.
The curved soprano saxophone is as easy to mic as the alto or tenor. A single mic on a floor stand, or single "clip-on" may be utilized in the same manner as for the larger saxes.
Another advantage of the curved soprano is the forward projection of the tone, enabling the curved soprano to play in better balance with a "big band" sax section. I like the use of soprano sax to play clarinet lead parts.
The above is not meant to confine these saxes to any particular role. Karina Rascher played a curved Buescher soprano sax with her father, Sigurd Rascher, in the famous Rascher Duo and Rascher Quartet. Straight sopranos being played with big band sax sections may be aimed straight out by tilting the head back slightly--like the old big band clarinetists.
With today's selection of soprano saxophones a saxophonist may chose the type best suited to his particular needs.