I've had an aspiration done. It was mostly just uncomfortable 3/10, with a few moments of pretty sharp pain more like a 6/10. However, those moments were brief and it was totally fine afterwards.

I also turned down some more potent painkillers beforehand, so if I had taken those instead of just the local anesthetic, it likely would have been less unpleasant.

Mild discomfort followed for a few days and within a week or so I had forgotten about it.