I am happy with the video quality of the D3300. Seems to work fine even for professional use. It has an audio in. Nice for a camera for this class. It doesn't have an audio out for monitoring. But the usual visual audio meter on the LCD worked quite well. As long as i keep the input within acceptable quality, the recording is good.
So, after a few months of using, my summary is this:
As a Still Camera:
1) Reasonable quality for its price. Lacking sufficient bit depth for adjustments but nice size compared to bringing a D800 around.
2) Lacking fast (large aperture) wide angle lenses except for 35 F1.8 DX (becomes 50 mm focal length) and 50 F1.8 FX (Becoming 75 mm focal length). The only thing i try to beat the system is a 24 mm F1.4G but this is a costly beast.
3) Kit lens is usable in Video and wide angle. Acceptable in 55 mm telephoto but try not to shoot anything further than 3 meters.
4) Kit lens has a silver ring. But it was already peeling the first 2 weeks i used it. Poor quality.
5) Wireless module WU-1a is a nice toy to have but features are limited. I.e it does not do time lapse and the timer is limited only to 2 seconds! This isn't enough for you to put your iPhone (operated via iPhone) back to the pocket.
As a video Camera:
1) Nice video quality with input jack
2) No complains.
Overall, nice size and weight but unfortunate for the lack of wide angle, fast aperture lens.
Sample video made with D3300 (some small parts are with Sony PJ660-EV)
http://www.youtube.com/watch?v=ImW_yWsp3k4