Good or no good?

[Iagainsti]

But in any situation where I don't know the tank (i.e., most DF runs), I'm always going to be initially happier zoning into a Fending tank, as it's the "safer" option.

There's no truth to that statement. Full slaying><Full fending brings me from 16k+ hp to 20k and change. A random Crit hit, or multiple hits from a pack knock that "advantage" right out in 1-2 seconds flat. Running full Vit is not safer, it doesn't allow say, a cure I cast instead of a cure II from a healer. There would have to be a large chunk of Vit from a higher tier set of accessories with the content staying relatively the same difficulty for that statement to ring true.