With a super wide angle lens, you not only get a wide view but also a lot of sky and foreground if you're using landscape. Sometimes, there isn't much there, and the original point of interest is lost and made so small in the middle of the image. Because that's what wide angles do, distort a bit of reality space. So, composition is a bit challenging. What appears to be a vast subject maybe only be at an arms length away.
Also, when people are in the frame, they really get this weird stretched Matrix looking distortion near the edges. For news and photojournalism it may be acceptable, but for friends to see their faces like roadkill will tell a lot on your photography.
Cheers!