I've considered doing the comparison as a image, but I'm really bad using Photoshop. Reading is good for you :D
Basic pros and cons:
Level 55 PvP set (Pontiff, Eradication, and Leopteryx sets)
- Ignores 2K PDEF/MDEF; a 1K DMG boost
- Initial Rage Minimum +30
- Extra 3K HP from END boost
- Slightly better stats than 50 set
- Rage Buildup is extremely slow for mages; slightly slower for archers and knights
- MDEF/PDEF ignorance is removed against bosses
- Stats are worse than 50 Legend set
- No extra gem socket
Level 50 PvE set (Magister, Harpy, and Titan sets)
- Extremely fast rage buildup (10 extra after each move)
- Damage increased by 300
- Legend set has better stats than 55 PvP set
- Legend set has extra gem socket
- No Initial Rage without clothing
- No HP boost from PvP set
- No MDEF/PDEF ignorance
- 50 set has slightly worse stats than 55 set
- After smithing to Legend quality, refines are removed.
Note that this information may not be completely correct; completely off Wartune Wiki
55 PvP set:
Max Enchantment Level: +18
Enchanting bonus: +900 PATK/MATK
Enchanting bonus: +563 PDEF, +563 MDEF
Enchanting bonus: +927 PDEF, +442 MDEF
Enchanting bonus: +927 MDEF, +442 PDEF
Enchanting bonus: +1958 HP
50 PvE set
Max Enchantment Level: +18 (Legendary Status +27)
Enchanting bonus: +802 PATK/MATK
Enchanting bonus: +1204 PATK/MATK
Enchanting bonus: +507 PDEF, +507 MDEF
Enchanting bonus: +761 PDEF, +761 MDEF
+826 PDEF, +401 MDEF
+826 MDEF, +401 PDEF
Archer: Unknown (Need help here)
Knight: +1239 PDEF, +599 MDEF
Mage: +1239 MDEF, +599 PDEF
Enchanting bonus: +1735 HP
Enchanting bonus: +2602 HP
What does this all mean?
Well, the most basic thing you should know is that the PvP set is useless after level 60-ish (probably 65) However, the 50 Legend set is better in stats in every way compared to the 55 PvP set.
Basically in normal PvE cases:
Legend PvE Set > PvP Set
PvE Set < PvP Set
However, the PvP set can outdamage the Legend set by 200 points in PvP uses; therefore it's a PvP set. The 2K PDEF/MDEF ignorance is essentially a 1K damage upgrade and the PvE a mere 300.
So in PvP cases:
PvP Set > Legend PvE Set
PvP Set > PvE Set
It also depends on your playstyle. If you want a initial rage minimum (for abilities like Suntoria and Agoran Shield) then the PvP set is for you. If you want immense rage buildup, then the PvE set is for you. It all depends on your playstyle.
PvP Set < Legend PvE Set + Clothes
Clothes give you Initial Rage, so it nullifies the PvP set's Initial Rage. The better stats on the Legend set make them outdamage the PvP set's PDEF/MDEF ignorance, so this rule is generally correct.
Another general rule after reading comments:
PvP Set is for burst damage
PvE Set is for long-term damage
Hope you like my guide!