The tanks have it good in terms of relative balance, especially when compared to SCH or the DPS category as a whole. All of them honestly are perfectly fine, but they have some irritations that need work. If you do decide to go DRK, keep in mind that the abilities are completely shite in the order that you learn them - the class tends to get progressively worse until certain levels, when you get a key ability that makes life better. Starting out, your complaint will be damage until 45, when you get Dark Arts. This ability coats 1/4 of your mana, but adds massive amounts of damage to many of your attacks going forward. AoE enmity generation/tankiness is going to start off until 56, when you get Abyssal Drain.That one is going to become a prime gcd for aggro generation and sustain. They actually nerfed how it works in your kit - used to be that DRK would hit critical mass in huge pulls and be able to basically sustain himself without a healer using that ability. After that, you're going to start feeling squishier and squishier until 70, and wonder what the purpose of the blood gauge is until 68. At level cap your kit comes together and it feels great - most of the complaints about DRK have to do with how power is distributed in his kit, not the overall power level