I'm not 100% sure as I have yet to use my sleeve, but my thought on the apple sleeve is that I take it out of my bag in the morning and take it with me to meetings. I slide the ipad out when I want, flip up the keyboard on top of it and start typing. I then can quickly access the stylus because it's in a designated, easy-to-extract pocket to write things down when I need to. Then I put it right back in its place, since the pencil seems prone to rolling around.
The SF bags one, to me, seems more like the bag with which I bring something to work, but not something that I'd want to take to a meeting and then have to pull things out of the bag and lay it on a table.
I might be having a hard time explaining the way I'm envisioning this, but hopefully that gives you some idea as to what I'm going for.