It all boils down to whether your reflexes are good. After a while, I just have this muscle memory on what to do so I don't miss anything the boss throws at me anymore. It's a pain when my character data is deleted and have to reset it though. -_- But ya those "end game" gears aren't actually end game. They're more like entry level gears to end game so don't worry about it and just find the class you like.