Gunslingers are very weak. Personally I think they should be buffed by Gravity. Yes they get 1200% damage but if they cast that skill and the opposing force is not dead they are basically screwed. For me Ninjas and Gunslingers have no glitches. When I tested them everything was working 100% correctly. Correct me if I am wrong but on eAthena forum the Gunslinger and Ninja classes are 100% completed.
I really believe the Ninja class is completely overpowered unlike the Gunslinger. I'm sure Gravity will tweak these classes in the near future.
I would say... Gunslinger is good to put in a server. Ninjas are horrible to put in a server.