I had a discectomy done on L3, and it was pretty painless.
I had mine done with an arthroscope, and it was done in a matter of minutes once I went into the surgery suite. I was awake during the surgery, and the most disturbing aspect was the weird pressure inside my back/chest, while my back itself was numb.
Unfortunately, mine did nothing to help my condition. It did significantly lighten my wallet though.

I did 2 rounds of epidurals that did not really help my back, but I did still have the L3 disc pressing somewhat on the nerve. The doctor cut out part of the nucleus of the disc in order to shrink that disc back into place, and that was that. The follow up MRI showed that the disc had then receded back to where it belongs. Unfortunately, L3 must not be the major problem in my back. I do have a congenital defect in my lower back ..... so there is something in there causing the problems I have had.
Back to the surgery, I have not had any side effects that I can think of.