The Phoenix has a few pros and cons.
Pro:
You can hit targets from cover where they can't hit or see you.
Massed, it can deliver an awesome alpha strike that can drop any ground target from full to dead. (In fairness, the Lancer can do this as well.)
No lock warning for the target, and immune to flares.
Does about 99% damage to an ESF; from full to burning with about 4 seconds of life.
Sounds awesome (SCREAMING FREEDOM EAGLE)
Each shot does a lot of damage (1500 IIRC)
Can be *sort of* dumbfired. (See note at bottom)
Con:
It can be shot down, and it's not that hard to do so.
The 300m range is rather limiting.
The TTK at range is rather low, considering while you're flying the rocket, you're not reloading.
Shooting infantry is a waste of time.
Its MAX damage is unimpressive.
While you can murder ESFs, good luck hitting one. An unsuspecting lolpodder is fair game, but any other flyer is a waste of time.
The turn radius is decent, but you're not going to be doing 180s.
Trial it to get a feel for it. It's kind of situational now, and I don't really see that many being used, especially after the lockons dropped to 250 certs.
If you release control early, it keeps flying in the same direction you pointed it, but it suddenly gains a *lot* of drop. An early release on a sure hit can save a second off your rearm time.
With the above, there's a trick to dumbfire it. Hold the fire key when you're locating your target. As there's no true dumbfire, this does nothing. When you're aiming where you want to shoot, hit your aim key. The rocket will instantly fire. Drop it immediately if you're right at the tank's butt, where you should be using this trick.
[When it first came out, it could one shot infantry and was hilariously overpowered.]