I think the Firespray is a good ship. It certainly can be competitive. However, it isn't as dominating as a 60 pt Turret, nor can it pull off a come back as well as 30-40 pts of Interceptor or Phantom. The comparison to 60 pts of an upgraded turret ship make sense, since the ship costs like 10 less pts when kitted out to an optimal build (Predator + Gunner + Engine, or anything else you can think of), so this sole ship performing less well makes sense, since it costs less points. And it also isn't glass cannon like interceptors and doesn't lose you the game in a single dice roll, which is why it costs more pts than the Interceptor and Phantom.
The ship DOES have a harder time vs arc Dodgers than Turrets do, but thanks to the rear arc, it does have an easier time than small base ships with only 1 arc.
I think the Firespray shines the most with a stress mechanic. Preferably Tactician or Imperial Kath + Predator + Gunner + Mangler. Stress dealing lets the ship truly shine. Gaining action and position advantages with ease, and countering arc Dodgers that rely on PTL, or jousters that require K Turning.
I'm not saying the ship is dominating, but it is an equally viable option at the moment, thanks to things like changes to the Phantom decloak and new Scum pilots.