Man I love Rugby, and I even know the whole "metres system" you all keep refering to (obviously used by everyone in the world cept us lol).
But you all lose me, big time in this debate, I have opinions, but some of the responses I read aren't even damn discernable by an american LOL.
To me, here in the US, speed in games like the NFL, it's not even debateable, because these guys were all measured in their 40's back in college or high school.
For those of you not too savy on 40's, it's "our" speed measuring system, we go mostly by short burst speed, which is what is most used in american football.
40's are the 40 yard dash, and the fastest (world fastest type people) are rated as such (Link Time!!)
http://www.parisischool.com/NFL_Combine_Training.html
Parisi Speed School: NFL Combine Training & Preparation Programs
Read up and see what we use for speed related info, trying my best to learn what it is you guys give as input and try to relate it to what I know from NFL and American standards.