...And then I went to DFO.

Problem with Summoners is people don't like how bad most of them are. Heard stories many just AFK or have their summons run around wildly instead of using Train and Mark the Target. That and some have problems seeing the screen when it gets clogged up with maximum summons.

Mages in general are a little problematic because of their squishiness, and Eles and Summoners are bad for PvP (too many srs PvP players in DFO).

Eles are actually absurdly good in PvP - they just aren't abused as much as they could be. They have 3 highly spammable projectiles that do high damage with low c/d, 2 defensive moves that are fast and provide significant knockback (one also can slowdown enemies), have decent defense from Mana Shield, can combo as well as any melee class (max upper -> Fire Pillar -> Frosty -> Pluto, etc), and have the most potential cspd of any character. They can charge attacks while moving and have a floating orb of hitstun to hide from melee classes in.