Well depends on what you're talking about when you refer to "Crusader"
http://www.wowhead.com/?spell=28004
You have Battlemaster, which is the godly enchant of all tank enchants, healing your whole group for 180-300 on proc. Put a Rogue, a Prot tank with low Speed tanking weapon this, and forget even needing to cure the group. Have fun though, the Void Crystals are 100g each, making the enchant cost nearly 400g. Totally worth it though if you're using a weapon you know you'll be holding onto. (one of the weaponsmithing weapons for instance)
If you're referring to the melee damage of the crusader, at the moment crusader is like 60str on proc, and as much as crusader procs, I'd probably stick with a +20STR enchant on both weapons, as +40STR all the time is better than +60/+120 occasionally. I could be wrong though, and this may apply differently with a rogue, but if you're a rogue you should be going for Mongoose anyway. Mongoose is like 800g+ though...and nearly impossible to get a hold of the mats.
Thats my 2 cents.