I'd go spear, no doubt about it. If you ask me, sword knights are just horribly weak compared to their spear brothers. The thing is, just as Glenn said, there's too many downsides to an Agi knight (Or just 2h vit, same thing in the end). Frenzy's useless due to dispell, and other than that, you don't really have anything good going for you. You're basically a katar sin without the good abilities.
Spear, on the other side, as already mentioned, has a wide array of useful skills, ranging from close combat ownage and mid range domination to long distance spammage. And, most important of all, you have a shield. Shield cards are, if my eyes, the strongest cards out there. Just a simple common one such as Thara Frog adds a total of 30% damage resist, which is a hell of alot of damage removed. From ALL PvP attacks. Since you're on a high rate, MVP cards should be obtainable, such as Golden Thief Bug and Maya.
And uh, Glenn, what horrible Lord Knights have you seen? 2k a hit from a spiral pierce is easily doable on a low rate server.