Ok let's start with Apex;
Apex is a defensive clan with members that are defensive and smart, people who don't take risks and will use every bit of their strength to claim their victory, an off side to them is that they aren't very good at pvp (in an offensive way) leaving them to rely on their bows and smart minds. Their Teamwork is amazing aswell.
ExiLe is a rounded clan with above average pvpers that know exactly know how to play aswell as how to work together. They are all balanced PvPers (Offensive & Defensive) with some exceptions of plain Offensive pvpers.
Sphinx is a rounded clan just like ExiLe but I've noticed that they don't work too well together, I've known this from experience and found out that we used to rush in relying on our PvP skills and gear. They have gotten better though and they have improved more then enough.
Earth I can't say too much since I haven't really seen them CB, but alone I can say that 3 of their members in their clan is enough to potentially takeout most lineups in the AU Clan Scene. You may guess who.
Amnesty is a very good clan I'd admit. They all play smartly but I can only say a few of them are above average PvPers. They have held their own against clans and are very good at working together.
Legacy is also a rounded clan but like Amnesty, I can only name a few that is above average. They play smartly and have managed to come close to beating ExiLe which proves they can very well hold their own.
In a PvP Scene, I'd say;
1. ExiLe v2
2. Sphinx
3. Earth.
4 Apex
5. Legacy
In a Clan Scene, I'd say;
1. Apex
2. ExiLe v2
3. Earth
4. Legacy
5. Sphinx
Note that this is my OPINION.