It is a tough decision, or at least would be, for me. My DH opted for the surgery even though, in his case, he knew it would be an extemely complicated whipple and a long shot for success. The good news is that his margins are clear and lymph nodes negative. The bad news is that he has had many complications that has had him in the hospital as much as home in the several months since his surgery. Our lives consist of hospital and doctor appointments and constant care at home. He does not have much quality of life, but is alive, months past his predicted life span. At the moment, you have hit us at a down point. He is very ill in the hospital at the moment. There is still hope, though, that he may turn around and return to the fight.
Please don't let our experience be the only one to guide you. There are many positive stories as well. Since you asked for good and bad, I thought I would chime in. If you asked my DH today would he do it again, he would probably still say "yes."