I am considering an equipment upgrade that will include a new wide angle zoom lens.

My question relates to the relative merits of a fisheye vs a rectilinear lens.

I believe I have a basic grasp of the technical differences and resulting visual differences between them, but I have no hands on experience with a fisheye lens.

Does anyone have any opinions one way or another?

Does anyone have experience with post processing a fisheye image to straighten it and remove the fisheye look, and how successful it is?

At this stage I am probably leaning toward a rectilinear lens.