I also did my relic via the DF after our FC raid failed it at like 1%---I tried...it was too cruel to expect a PLD+WHM(with raise weakness) to two-man the last 5% or so of Titan---after the 1% wipe nobody wanted to try it again.

My DF runs felt like half the runs couldn't break the core, the other half can break the core but get wrecked quickly afterwards. Perhaps 15% of the runs were more or less stable but would always have one or two newcomers who keep dying before the core or after the core (sometimes both). When the DPS were great, one of the healers would be dying all the time. When both the healers were great, half the DPS would be dying repeatedly.

I think it was three weeks of DF on and off, then I bumped into an FC farming group, did lolPLDdps and basically got carried to my relic because the group was performing perfection itself.