Thought I'd give an update. I've been using the calories burned given by my exercise bike, the lower estimate, for the past couple of weeks, and have lost pretty much exactly 2 pounds per week, as I would expect if that estimate is correct. So I think the machine estimate is pretty accurate after all. Good to know!
As you hold on... as long as you do what's in your heart... I believe you can do the right thing.
current weight: 155.4