Not really, because your comparing bananas with apples.
Your comparing ARGB bitmap graphics with YUV420 overlay, two different technology’s.
YUV420p is a 12bit format vs ARGB a 32bit format.
http://en.wikipedia.org/wiki/YUV
ARGB = 640x480*4 = 1 228 800 bytes
YUV420p = 640x480*6/4 = 460 800 bytes
ARGB takes 266% more space then YUV420p, conversion & bandwidth is also costly when you most use ARGB.
So basically the AmigaONE-X1000 has to work harder to display the same graphics.
Sorry, but that's just a (lame) attempt of a academic excuse.
I compare exactly one thing:
How fost does my powerbook replay a certain video and how fast does it an X1000 or Sam460.
Today, reproducible and reliable. Why the result is like it is is not of my interest. I wanna watch that video, not think about the technical internals. And I give a certain brown matter about what could be in future. It matters what's actually there. And for that i provided numbers. They speak for themselves.
But hey, yeah - two more weeks and everything's brilliant of course.