I'll never understand why people downplay the strength of DK tanks. Anybody can hold threat and eat the damage, but DKs completely ignore a whole bunch of mechanics and often top the meters for dps on fights with adds. They might get spiked a little harder than a warrior or paladin, but it's not enough to kill them if they are geared for the content, and it's not a strain on the healers because of how much self-healing they are able to put out with Death Strike/Blood Shield. The only real drawback Blood has is that while every other class got abilities and hotkeys pruned in WoD, DKs somehow ended up with more shit to bind than ever before.
That's just first-tier, intentionally shitty itemization (unless you're a warrior who wants crit). By the end of BRF you can have a full set of gear focused almost entirely on mastery and multistrike, a little bit of haste and versatility, and basically no crit at all.