Arctic Silver isn't a rubbish paste for 200 hours then suddenly becomes really good. It's okay out of the box/tube and improves very quickly, peaking in performance after 200 hours. I'd guess it's at 90% of it's peak within a few hours. But this is off topic anyway.
I wasn't suggesting that it's rubbish paste for 200hrs

, what I should have asked was "will it get better as it reaches the 200hr mark and then stay steady beyond that" as I am a little curious as many people have suggested that it's better than "okay out of the box" as you put it. And if I haven't applied it correctly(I believe I have) I didn't want to wait until that time as the temps would have risen (only slightly of course) nothing to be worried about, obviously if MX-2 shows very little increase in temps after application, that would be preferable in my mind. Again not worried about temps but the cooler the better if you see what I mean.