Also, you need to be careful against crews that can dispel Protect . . . just something else to be on the look out for, from someone who used The Guardian with LadyJ all the freakin time.
Putting up Disrupt Auras that cover LadyJ is amazing as well. Especially since you tend to get right in the thick of it. You do have to be wary, as was stated, and don't just go marching up the middle. You'll last a lot longer if you can minimize the amount of strikes coming in.
Oh, and if you get bored . . . and use a totem for some reason, you can always have it give the Guardian Melee Expert . . . not bad, especially with the shield attacks to finish off wounded models or just put damage on ones with high Def.