
As far as I've seen, VIT continues to be a flat increase to HP per point. (Damned if I remember what it is, though... I want to say +15 HP/VIT, but that's probably not right.)
Block rate versus block strength, at its core, comes down to mitigation type. It appears that XIV uses a separate roll after the attack roll for blocks, as I've blocked crits before and mitigated them down. So, ultimately, overall mitigation for a block can be calculated as block rate * block strength (if you block 50% of the time for -15% damage, your total mitigation over time is -7.5% from block). However, in practice, all fights are the "short run," to borrow an economics term, and so block rate and block strength have different "feels".
A high block rate and low block strength means that your mitigation is more consistent, so you block for less but do it more often. This produces a low variation in mitigation such that your health slowly decays by a consistent rate. A high block strength and low block rate makes your mitigation more random -- similar to an avoidance tank. You block for more but it happens less often. The result is a high variation in mitigation and a "spikier" health curve.
Of course, what you really want is high values in both, but assuming you can't realistically get that, I think most healers would prefer high block rate, as it makes their jobs easier. They can more easily predict your health decay and time heals better for maximum efficiency (despite XI players in XIV demanding you overheal and keep them topped up all the time
). However, high block strength has its place, too. Encounters where mobs generate unavoidable massive damage attacks can benefit from a chance, however small, to mitigate more of that damage. Solo, high block strength can make you feel more survivable.
EDIT: As far as tanks are concerned, though, I'd still go with the STR. Survivability doesn't seem to be a big problem with tanks in dungeons and FATEs so far; threat, however, is. Anything to help increase your threat generation is good, and that your mitigation improves as part of it is a nice side effect. Also, killing faster really what ultimately matters (no one got XP for surviving a long time, after all
), so adding damage is also good. All in all, STR seems to be the best tanking stat based on the available data thus far. Endgame dungeons and raids, however, might change that.
Block rate versus block strength, at its core, comes down to mitigation type. It appears that XIV uses a separate roll after the attack roll for blocks, as I've blocked crits before and mitigated them down. So, ultimately, overall mitigation for a block can be calculated as block rate * block strength (if you block 50% of the time for -15% damage, your total mitigation over time is -7.5% from block). However, in practice, all fights are the "short run," to borrow an economics term, and so block rate and block strength have different "feels".
A high block rate and low block strength means that your mitigation is more consistent, so you block for less but do it more often. This produces a low variation in mitigation such that your health slowly decays by a consistent rate. A high block strength and low block rate makes your mitigation more random -- similar to an avoidance tank. You block for more but it happens less often. The result is a high variation in mitigation and a "spikier" health curve.
Of course, what you really want is high values in both, but assuming you can't realistically get that, I think most healers would prefer high block rate, as it makes their jobs easier. They can more easily predict your health decay and time heals better for maximum efficiency (despite XI players in XIV demanding you overheal and keep them topped up all the time

EDIT: As far as tanks are concerned, though, I'd still go with the STR. Survivability doesn't seem to be a big problem with tanks in dungeons and FATEs so far; threat, however, is. Anything to help increase your threat generation is good, and that your mitigation improves as part of it is a nice side effect. Also, killing faster really what ultimately matters (no one got XP for surviving a long time, after all

The Freelance Wizard
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((about me | about L'yhta Mahre | L'yhta's desk | about Mysterium, the Ivory Tower: a heavy RP society of mages))
Quality RP at low, low prices!
((about me | about L'yhta Mahre | L'yhta's desk | about Mysterium, the Ivory Tower: a heavy RP society of mages))