The feat Wings of Air gives a supernatural fly speed equal to your base speed, and is pretty much an auto-pick for all Sylphs.
However, Air Supremacy, a trait of the Air Wizard School, gives the ability to cast Fly on yourself at will as a supernatural ability.
I've already set down the Air Wizard School, so at that point is getting Wings of Air worth it?
I've never had a flying character before, so I don't know the difference between having a Supernatural Fly Speed, and being under the effects of the fly spell.
For one, I'm already using feats to accomplish something I would already be able to do. But I'd have to refresh the fly spell, and cast it, meaning it wouldn't be available in a pinch if I didn't already have it running.
The Fly spell seems to be locked at 60 ft/round, would having a Supernatural Fly Speed of 35 mean I'm stuck at 35? Or can do a run action like one would do with on-land movement?
I'm very unclear on what each of the abilities actually does. Hence why this is in Rules Questions.
The "run w/ flyspeed" question has been asked before, such as Here ... brief search, still no answer found. Still looking.
No, you would not be "locked" at a speed of 35. The Fly spell Enables you to fly at 60.
The subject can fly at a speed of 60 feet (or 40 feet if it wears medium or heavy armor, or if it carries a medium or heavy load)
Emphasis mine.
The above covers speed. The other big difference you should be aware of is the wizard ability can be dispelled due to being a spell-like ability. Depending on the campaign and DM that may or may not come up.
I think I've seen it stated somewhere you can do a 'run' fly. Or even a double move. Nothing official though so run it by your DM and find out how they would rule to know for sure.
I think your Sylph can also increase his base land speed through items and feats to increase his fly speed as well. Or at least I'd allow that in my campaigns.
There's an alternate racial trait (which I took) that adds 5. That's how I got 35.
Even if it was dispelled, it can be cast at-will infinite times per day, so it would have to be some sort of anti-magic field which already nullifies supernatural abilities.
So it seems the Pros and Cons are as follows:
Pros:
Don't have to cast it once every [level] minutes.
It's active whenever I need it, don't have to waste a round casting if I forgot to cast it a while ago.
Potential to move 140 feet in a round by air.
The feats also grant +4 on saves vs electric and air effects.
"Good" level maneuverability
In character, the character would probably prefer this option.
Cons:
Costs 2 feats
Walk speed is only 35, not 60, meaning you move slower taking a move action and standard action in a round, but move faster when taking full move actions.
Out of character, it's a hefty cost for abilities I already partially enjoy.
Alternate rules question:
If you have a natural/supernatural fly speed, and fly gets cast on you, can you choose which fly speed to use? 60 if you're walking and your super/natural speed if you're running?
Edit: Actually, my DM is pretty loose about homebrew, I'mma just see if he'll changing Air Supremacy's level 10 ability to just become a supernatural flight speed for simplicity's sake.
It seems very possible to choose, given the above. But I personally see no reason. If you've got a flyspeed despite being dispelled, you're not going to immediately fall. Anti-magic fields cancel both anyways. Keep in mind this is the Rules section, not advice; We`re only interested in your rules questions here.
@Aleron ; You're right, it seems the general consensus that you Can 'run' whilst flying. This is decided mostly due to to the wording of 'Running' (says Speed, not a particular type of speed), and the definition of Speed (which encompasses multiple types of speeds). You can't run whilst climbing though. Swimming with a swimspeed can 'run' in a straight line. See those respective skills, for the proof.
As far as advice is concerned, I've been playing a sylph wizard with the 2 feats and regretted it. 2 more feats would be more use for eg Spell Penetration or metamagic or... Spending a spell slot or 2 is much cheaper.