Stuart - I'm not but I have one of the Kata backpacks and all the tech specs are on the Kata website. I found that the Kata backpack was much lighter than its counterparts from other manufacturers. Sorry if this doesn't help and you've already seen the specs.
I'm not exactly sure about that Kata bag as we have not carried it, but Kata just released a new line of lightweight rollers that have a removable wheel assembly for carrying and for saving weight. We picked them up and they are getting very good comments and reviews.
The Kata Pro-Light FB-76 looks to be the same dimensions (interior) as the Airport Security.
It's about $80 cheaper and quite a bit lighter.
That said, the Security is a very nice bag and our best-selling roller.