Spell Speed and Piety!

Okay, end joke.

It's worth noting that weapon slots typically take the longest to be replaced. This is especially true if you plan on being diligent enough in the Relic Upgrade Progress to reach Excalibur. It is for this reason that it is never remiss to put Accuracy on the Relic. Your weapon is the last thing you want to switch out to meet an Accuracy cap, especially if you can't sidegrade it.

If you aren't terribly interested in the Crit/Det Novus, then Parry is really the only other option. I wouldn't recommend that you worry too much about it anyhow; all Secondary Stats provide approximately the same benefit, mainly not much at all.

Here's a couple of numbers I've scrounged up for the extremes stat wise(this is in respect to the entire gear set, not just the weapon):

A full Parry build will theoretically, for a PLD, confer an over 50% chance to mitigate a physical attack.

A full Crit/Det build will theoretically, for a PLD, confer an additional 7-8% damage dealt over the full Parry build. I did that testing at i115; the ratios will change as other stats do.

A full Skill Speed build will definitely make you run out of TP.