Ok, so my main question throught this rant will be, Is there a difference between being "Claimed" and being "Infected"?
Here is what I am basing this question on.
Claire, aside from being loony as all hell (singing to herself in the hole and the dead animal baby thing in the crib) seems like she still has some of herself in her. She didn't blindly listen to Flocke when he asked her to go into the Temple, she even tried to get out of it. All she really seems to care about is surviving and finding her son. Yeah she has been a ruthless killer of The Others, however you can chalk that up to her being manipulated into thinking they had Aaron and stopping at nothing to get him back.
Sayeed, on the other hand died. He was dead for 2 hours and suddenly came back to life. It took some time for the evil in him to come around (just as Dogen said), but now he really embraces the evil. In fact he seemed to really enjoy killing Dogen and Lennon, when in any other episode that he killed someone he showed some remorse (except for when he did the bad ass hands-tied-behind-his-back neck break during the Other's beach attack).
With all of that being said it seems to me that Claire might still have her free will. She can assess the situation and still make decisions for herself, even strike deals with Flocke (I'll go in if you promise not to hurt Aaron). Where as Sayeed seems to be Flockes Soldier, don't ask any questions just do whatever evil he is instructed to do.
Or maybe if you think of it this way. Claire and Sayeed are now Flockes puppets. However, Sayeed is more of a ventriloquist dummy, Flocke controls every part of him from his movements to what he says. And Claire is more of a marionette, Flocke can move her as he wished, but sometimes the strings can get tangled or even cut and he can lose a little bit of his grasp on her.
Does any of this long redundant rant make any sense?