I had this exact procedure done about 10 years ago and I love answering this question....crazy, I know.
I had prepared myself for pain worse than childbirth, difficulty eating, sore mouth, bruising, swelling, etc. As it turned out, I had barely any of it!
The day of the surgery my oral surgeon gave me a Valium just to help me relax. The surgery lasted a few hours. I felt no pain at any time. Afterwards I had a retainer type thing to cover the roof of my mouth and some play-doh like substance covering my gums down below. I took minimal pain meds afterwards and was back to work quickly....had the surgery on a Friday, back to work Monday.
I don't have a high tolerance for pain, and I can be a wimp. I really had no issues. I don't want to set you up for false hopes/expecatations. I just want to give you my account of the procedure so that you can weigh it in with others.
Good luck to you. If you have more questions, feel free to conact me.