Summary: I love this fish eye lens...it takes very good pictures... For photography, if you just want to have fun, this is the lens to have...it has obvious distortion but that it what you want on a fish eye right ?!
Summary: Amazing is all I can say. I shot a wedding on a boat with this lens as I knew the coverage will be limited. I'm glad to have carried this lens with me (rented). It's heavy duty and while it does make a buzzing noise it's not loud nor could be heard especially at an event. It's relatively small, compact like the 50mm f/1.8 lens but the hood is made of metal with metal mount. Tiny but made very well.
Summary: This is the first fisheye I've owned and this thing is a lot of fun. Its fast, sharp and takes great pictures. Obviously there is distortion with it being a fisheye lens but fixable with DxO or similar software.
Summary: This Fisheye is a great lens. There is an issue with the lens cap not staying on, but there are fixes, just google for some ideas. Whether you use this on a full frame or APS-C camera, the effects are still worth having it in your bag. I wish Canon would replace this discontinued lens with another option under the $1000 mark (right now the only Canon fisheye available is the L).