According to the official Combine weigh in numbers Akers was 4 lbs heavier.

I believe the Rams have him 6 lbs heavier.

Everyone keeps saying that Akers is so much bigger but I'm not seeing any official confirmations of that.

Also not sure Akers is faster. Henderson actually clocked slow on his official 40 time in the high 4.4's. Rumor is that he strained his hamstring on that run. And that rumor is supported by the fact that on the run preceding the offial time, he clocked in at 4.37.