d20 aerial combat

A lot of you tards don't understand how shit flies.
All flying creatures move down twice as fast as they move up, eg. they can move down 10 feet for every 5ft of flight movement spent (without losing control).

Perfect maneuverability
A creature with perfect maneuverability can move however it likes with no restrictions. It can hover, do 180 degree turns and ascend/descend at will, in any manner it wishes, without costing any extra movement.

Good maneuverability
A creature of good maneuverability is restricted in the following ways:
- It must move at least 5ft in a forward direction in order to make a turn. It can turn up to 90 degrees to move laterally on its next 5ft of movement, or turn 45 to move diagonally.
- It can spend 5ft of movement to turn in any direction it chooses.
- It ascends at half speed (10ft of movement spent for 5ft vertical)

Average maneuverability
- It cannot hover. If it moves less distance than half its maximum fly speed, it must land. Otherwise, it falls 150ft. If it's still airborne on its next turn, it may make a DC20 Reflex save to right itself. If it's not, it takes falling damage.
- It must move at least 5ft in a forward direction in order to make a turn. It can only turn 45 degrees to move laterally or vertically per 5ft of forward movement. In other words, it has a 15 foot turning radius.
- It may spend 5ft of movement in order to make a 90 degree turn. This 5ft doesn't count towards its minimum travel distance.
- It must fly for at least 5 feet level after descending before it can ascend.
- It ascends at half speed (10ft of movement spent for 5ft vertical)
- It must move forward at least 5ft for every 10ft ascended.

Poor maneuverability

- It cannot hover. If it moves less distance than half its maximum fly speed, it must land. Otherwise, it falls 150ft. If it's still airborne on its next turn, it may make a DC20 Reflex save to right itself. If it's not, it takes falling damage.
- It must move at least 5ft in a forward direction in order to make a turn. It can only turn 45 degrees to move laterally or vertically per 5ft of forward movement. In other words, it has a 15 foot turning radius.
- It must fly for at least 10 feet level after descending before it can ascend.
- It ascends at half speed (10ft of movement spent for 5ft vertical)
- It cannot descend at greater than a 45 degree angle without losing control.
- It must move forward at least 5ft for every 5ft ascended.

Clumsy maneuverability

- It cannot hover. If it moves less distance than half its maximum fly speed, it must land. Otherwise, it falls 150ft. If it's still airborne on its next turn, it may make a DC20 Reflex save to right itself. If it's not, it takes falling damage.
- It must move at least 10ft in a forward direction in order to make a turn. It can only turn 45 degrees to move laterally or vertically per 10ft of forward movement. In other words, it has a 30 foot turning radius.
- It must fly for at least 20 feet level after descending before it can ascend.
- It ascends at half speed (10ft of movement spent for 5ft vertical)
- It cannot descend at greater than a 45 degree angle without losing control.
- It must move forward at least 5ft for every 5ft ascended.

Summary
As I've said before, the difference between perfect and good is not that huge. Perfect allows for faster vertical movement, but it's rare that you will need to make a >90 degree turn in the air, so the advantages of perfect movement are mostly limited to extremely rapid ascension. It is possible that on your next turn, you may need to make a greater than 90 degree turn relative to your travel last round, so perfect is still nice.

The difference between good and average is huge. An average creature can't start a fight on the ground or it won't really be able to take off without fleeing first. Even if it does fight in the air, it can't hover so it is extremely limited. It can't take full attacks or non-movement full-round actions while flying, so the only creatures that should employ this is creatures with useful standards. They can also use the Flyby Attack feat to get a single non-provoking attack in, but against multiple characters that only stops AOOs from one. This is worse too because they have a turning radius (ew) and can't ascend without moving forward (also ew). Against a divebombing aerial attacker, even with flyby attack, characters can stand in a line and let the AOO chain fly.

Average and poor maneuverability don't have much difference. Divebombs were already bad for average, so the fact that they're worse for poor doesn't mean much. Compared to an average flier, aerial engagements come down more to who has the faster flight speed and the better ranged standard options more than who has the better maneuverability. Like with average, these creatures pretty much shouldn't fight in the air against anything that has good or better, or they will literally be giving away AOOs all day.

Clumsy creatures have a horrible turn radius and are pretty much useless in aerial battles except as ranged combatants (or carrying them). Even then, the 30ft turn radius is so bad that it might not be able to put itself in range, forcing range increments and limiting medium range spells and abilities. These creatures are better for travel than combat, but should only really be employed in combat against non-fliers and should utilize ranged attacks.