I occasionally shoot video and have been very satisfied with the quality. A few things you should review about the settings:
1)There are TWO live view modes, Hand Held and Tripod. They operate video very differently, so review the manual (P58,59). In summary: Tripod mode - you can select the aperture. Camera can also AF during recording, or preset focus using the AF Button. Hand Held mode - Camera selects shutter/aperature. No AF during the recording
2)Movie Settings: Under "Movie Settings> Quality" you have 3 options: 1280 x 720 640 x 424 320 x 216
I find the 320 is rather fair and only good for small sized movie images. I would not use this setting 640 - is very good 1280 is excellent, but creates huge movie files.
The internal mike work well, as long as the subject or sound is close enough to the camera. The camera has an external mike jack, and I do use an external mike, mounted on the hot-shoe. Helps a lot on sound.