CraveTV doesn't support Android TV boxes directly. Here are a couple of excerpts from their FAQ that apply:
Which devices does CraveTV support?
Android tablets and smartphones running version 4.0+
How much bandwidth will I use while streaming video on CraveTV?
This will depend on the device you are accessing CraveTV with. If on a mobile device, then it can range from 0.2GB to 0.9 GB per hour. However, on many connected devices (AppleTV, Chromecast, etc.), the range of HD streaming rates are between 0.9GB to 2.4 GB per hour.
My guess is that your Android box is being treated like a mobile device and not getting an HD stream. Do you still get a stutter if you stream CraveTV on your PC?