So Im thinking of getting the Keepall 45 for my husband so we can match. The SA the 45 would be the largest I'd want to go for a carry-on. Could anyone confirm this? The other question is....why is the keepall WITH straps so much more than the keepall w/out straps? A good couple hundred $$ more. I can't access the elux now, but I know the difference is more than $300. Just curious. For practicality, I will have to get the one WITH straps b/c I don't want my husband to be forced to ony carry it by hand. but geez. Its just a strap!!!