Looks like I need to chip in here.
First off, above all else, the difficulty of the fight depends less on the power of the class and more on the skill of the opponent. Case in point, as a mid-30s Dragoon, I took on and beat a 50 Dragoon and a 50 Ninja simultaneously because I knew how to fight each class, and how to use the terrain that was available to me. Also, ShadoWall555 is a terrible Dragoon, so that had something to do with it.
Dragoons are in an interesting position. We're very much a specialized class, moreso than the other warrior classes. Paladins can soak up insane amounts of damage, but have Soulfire, and can revive. They also do moderate damage when up close. Dreadknights have a variety of skills available that make them more versatile overall than just doing damage, which they have a solid ability to do. Their DoT can make the difference between a win and a loss, and their defensive ability allows them to stick around in a fight, becoming very valuable to group fights. Samurai have the ability to kick out damage and still be able to survive getting knocked around, and also have a DoT.
Dragoons, on the other hand, are a utility class. Honestly, a good Dragoon is the cheapest warrior class to play by far, as our weapons only need one material, we only have one piece of diamond armor (leggings instead of chest), and we have the ability to disengage to preserve our stuff. In combat, our entire class is built around mobility. In combat, jumping is a good way to start a fight (especially if Quake gets implemented properly), but isn't my first choice, as it burns up mana that could be used for a disarm. I only use this if going against a caster or a ranger. The reasoning for this is simple: We have no ranged offense or defense. We get Impale, which lets us hit about four squares away, and slows a target. That's our only offensive ability, and it only hits for 14, with a mana cost that takes away a jump opportunity. We hit for seven damage, which is more than Paladins and Dreadknights, but we have no other offensive capabilities, so it's difficult for us to bring a high defense target down.
The combat dynamic for a Dragoon is very similar to that of a caster: A Dragoon that runs out of mana is fucked, and we don't have consume. Everything we do requires mana. Jump (Superjump even moreso) costs mana. Disarm costs mana. Impale costs mana. Charge and cleave are irrelevant. Basically, you have 100 mana, which gives you roughly six ability uses (counting in fight recharge). That's a rough balancing act, especially against ranged classes. Against a ranged class, you HAVE to close the gap, so that means at least one jump, often two (with three seconds in between), and an impale to keep them close. Beat on them as much as you can, and if they're not dead when you're done, retreat to recover mana and then re-engage. This, of course, all relies on not getting slowed down, rooted, or DoTed, and every class has at least one of those abilities in some form. If one of those happen, you're in trouble. Dragoons take time to kill their targets. Our mobility is what allows us to keep our opponents close enough for long enough to do so. Without that, we have all the offensive ability of crafters. Other classes balance their mana between damage and utility. We balance mana on staying mobile long enough to survive the fight, even if that means we have to retreat, recover, and re-engage.
In conclusion, Jump is far from just something extra given to a class that can stand on its own. Jump, and our mobility, are the core of our class. If you played our class, you'd see that. If you're getting your ass handed to you by Dragoons, study and use the abilities of your class to counter them, not tell us what needs nerfed with ours.