I love my 7D. Far better than all of the others below it. Not full frame, but has amazing AF. Having said that, if I were to buy a new camera right now, and had access to FF compatible lenses, I would suggest the new Full Frame 6D, but that's just my opinion. Otherwise, you would never be unhappy with the 7D
I've shot thousands of photos and videos with my 7D. It's an excellent camera. The only thing I can criticize about it, which is true of all APSC cameras, is the noise level at high ISOs. Once you get much above 3200 noise gets worse and worse. It can be removed with software of course though. Still, it's a nuisance.
Yes - as is pretty much every single DSLR on the current market by Canon, Nikon, Pentax and most of the other brands.
Now if you want a more detailed answer you've got to say what its good for - that is what your needs and requirements of a camera are. What kind of situations and shots are you going to be involved in - what kind of lighting, subjects, environments. What do you want from the camera - furthermore an idea of what you already own such as lenses, flashes etc.. as well as what your aims are - what is the camera hoping to give you that what you currently have isn't giving you.