I have leveled both a Dragonknight and Templar to Veteran level 1 in the betas. And honestly, I have a hard time choosing between them. I like them both, but for different reasons.
I have tried full plate, full leather, and mixes of plate and leather between both classes. I really did not have any issues with any of those combinations.
The Dragonknight is more "tanky" and relies heavily on those defensive bonuses. That means, if you find that your small heals aren't overcoming the damage being taken, there's not a whole lot you can do about it. Once the fight starts, you're committed.
The Templar was a bit squishier, but not as much as say a Nightblade or Sorcerer, but noticably less than a Dragonknight. However, the Templar has very strong heals. So if the fight isn't going well, you can basically "run laps" and heal up and go at it again. The Dragonknight really can't do that.
So by comparison, the Dragonknight takes less damage, but doesn't heal as well. The Templar takes more damage, but heals quite well. If you are fighting someone who crits alot, or has heavy damage spikes, the Dragonknight will probably work better. If you are fighting multiple enemies with standard attacks, the Templar probably works better.
As far as damage output goes, I really didn't see much benefit from Molten Weapons. Yes, numerically there is an increase, but not really 'game changing.' And you have to keep spawning that buff. In long fights, when you are focused on your targets, without some kind of UI help, its easy to forget to 'rebuff' during a fight. Small fights are over quick, so that's not a problem except that you have to rebuff in between almost every fight and that got tiresome.
Personally, the two classes played so well, it all came down to one spell that I absolutely loved. Binding Javelin on the Templar. The Javelin knockback is superior to the Stonefist knockdown. With the knockdowns, enemies are "stunned" until they get back up. With the Javelin, enemies are "stunned" until they get back up AND close the distance again. So with a bow (yes, I tried bows on both Dragonknight and Templar), the Javelin really shines for its CC ability. And since I'm going to go with the bow as my primary weapon, I'll probably go Templar.
But if I were going to play a melee style, I would have to think very hard because the Dragonknight does do very well in close quarters melee combat. If the 2H was your main weapon, you might actually like the Dragonknight as your first choice.