FWIW I'm no authority but happy to share my biased novice perspective.
Pros for importing into Aperture:
Easy workflow to import everything from my media cards to one location in one step
Very easy browsing and viewing of videos on Apple TV
Easy to create decent slideshows with video within Aperture (see http://support.apple.com/kb/VI179)
I like having both videos and photos of an event or project located in one place instead of having to navigate to a second software program to see if I took any video
Aperture videos are available in the events library in iMovie (because of this I haven't been compelled to import a video directly into iMovie yet)
Cons for importing into Aperture:
If you have permissions or other system issues it can be very difficult and time consuming to get iMovie to recognize Aperture videos (for most this isn't an issue)
Some experienced video editors recommend against managing videos in a software program designed primarily for photos or having it managed at all
My bias comes from being a family guy who uses Apple TV a lot and wants things simple and to spend as little time as I can on the computer. Experienced video enthusiasts can provide a broader and more thorough explanation of the pros and cons. Wish you the best setting up your ideal workflow.