This post is not intended to compare DKs to paladins. That's overdone and usually pretty stupid. I instead want to compare DKs to every other class, and show that in some ways they are far better. It's not about class strength (I make no claims on balance or lack thereof), it's about how well the class works with itself.
I've heard runes compared to energy. Runes are far better than energy. They're flexible. Abilities have costs, but they aren't always at the cost of each other. Rogues almost work in opposition to themselves. You need combo points for finishers and to get those you need to use special attacks, but they all use the same energy source. The result is that to be able to use a finisher you have to burn the resource you use for that finisher. Sure it regenerates quickly, but it still feels counter-productive.
No class fits together as well as DKs. Their abilities complement each other. If a talent replaces a baseline ability, it truly replaces it, without ambiguity of one spell being better here and the other there and I guess I can find another hotkey somewhere... (I'm looking at you, seal of command) Did I just say they complement each other and then say they replace each other? Oops. Back to compliments: I am a fantastic person.
I play unholy, so this may be a spec-specific thing. Frost looked weird and Blood felt too much like a ret paladin. But some of this is general. The disease-strike combination works very well. It's almost like combo points, except not so limited. You can use strikes any time, they'll just be noticeably weaker and using a different strike isn't going to ruin the diseases you built up. What other class builds up like this? Oh sure, there are things like curse of shadows (elements? What is it these days?) or the old judgement of the crusader, but they're so simple that they feel less like a synergy and more like just an opener that does no damage.
Now there is a bit that may seem confusing. The diseases generally require frost or unholy runes. My biggest strike for unholy uses both and works off diseases. This is counter-productive, right? Sort of. I have a talent which converts my blood runes into death runes (universal runes) when I use a weaker strike. Every two times I use the weaker blood-based one, I convert enough runes to use my frost/unholy-based strike. The weaker one uses different runes, so it's able to be used while I'm waiting for frost and unholy runes to come up. It's actually a great combination, while my strongest ability is down, I can use a slightly weaker one at effectively no cost and it converts new runes needed for my strong attack.
I did not emphasize that the death runes work universally and can be used as unholy. What does this mean? It means more corpse explosions!
The rune conversion reminds me a bit of the old mojo system that someone suggested for shamans. You do one sort of activity in order to fuel another and they complement each other. In the case of shamans it was healing and damage each reducing the cost of the other. For unholy it is blood attacks increasing resources for frost/unholy attacks. It also works for additional blood attacks, but if you're only using blood runes for blood attacks, why bother with the talent? It's a flexible system and quite a bit of fun.
These get a heading because of TL;DR.
There doesn't seem to be a 'correct' spec, yet. This is great because it allows people to play what they want to play, how they want. There's only one way of being ret DPS or a prot tank. There's only one shadow tree and one rest tree (okay two, but you can only pick one). DPS classes have had this for a while, this variability of choice for how to play within the same role. But they obviously have had higher and lower trees. Some specs were for PvP and others for PvE. DKs don't appear to have this problem. You play what you want and it's the best spec you could have.
I'm sure part of this is ignorance. DKs are still new. Their resource system is very complex. There are not the clear specs of other classes which have been developed for four years and simply updated each patch. Maybe there is a best DPS spec and a best tanking spec. But, we don't know and I doubt we will for a while.
Spec freedom, truly choosing how to play, that is a great thing. No other class has that. Above the synergy and lore and cool animations, this is what makes the class work better than any other.
I don't like the feel of DK tanking very much. Hopefully this is due to inexperience and being only 63. It feels too much like when I'd tank as ret. I didn't feel like I had tank abilities, I just held aggro. DKs hold aggro. They have all sorts of activated mitigation, but I'm too used to warrior and more recently paladin activated abilities: you save them for really bad times. I constantly forget bone armor. I should be using icebound fortitude every other pull, maybe. I don't really know. The lack of a shield, or turning into a near, is what throws me off. I know that I have increased armor in frost presence. I know that I have increased health. I know that I parry more than normal. But still, where is my damn SHIELD!? Maybe I'll get used to it eventually, but in the meantime it feels weird to me.
12 minutes ago