Mm, the links do not work for me. x.x
Anyhoo, in general without taking any variables into account vitality > toughness methinks, 'cause it's the only stat that gives protection vs condition damage and it also helps vs non-condition damage (just not as well as toughness), but which is used depends on your spells and playstyle imo. If for example you have a ton of condition removal, toughness would be better. If you have a lot of CC/evasion or are very bursty as Devve mentioned then vitality may be better for a bit of overall defense.
When it comes to straight tanking damage though (for long-lasting fights), mitigation always trumps health. Condition removal is much more reliable than avoiding damage through other means, and heals are stronger with a lower health pool as they'll heal a higher percentage of your max hp.