As a few others have alluded to and posted time results, exiting back to the menu from anything is much faster now. Everything else is only marginally faster, particularly launching apps. Of course, I'll take what I can get.
I think my biggest problem is that, like the 3DS, there are certain apps that should ALWAYS be loaded into memory, that should come up INSTANTANEOUSLY.
For example, why is Notifications its own app that isn't always loaded into memory, and why do I have to wait and launch into it to read these three word notifications? Could you imagine if your phone or Facebook was like that?
Things still need to get way better to get to that 5 second and under mark. Bring on the Summer update. My new expectations is that it'll get almost everything within the 10 seconds it takes to close apps.