Yes, my surgeon's told me how much I could expect to lose total after surgery and that it was possible to exceed that expected percentage. My surgeon said "you can lose 60% of your excess weight or more" basically. I'm in the "or more" category at the moment. In my experience, they want to give a conservative estimate since not everyone makes it to their expected loss. Also at each post op visit where weight loss was monitored (ie: not just the staple removal appt) they would say if i was on track or exceeding expectations. You can certainly call the office's nurse line and ask approximately what you should be losing per month. And yes, I think 40 pounds down 6 weeks out sounds like fabulous progress--but I'm not your surgeon so I don't reeeally know
I didn't reward myself with prizes because that would personally take me down a path of rewarding myself for something I really just needed to do for my health. I do a little cheer every time I meet a goal and maybe get a coffee that week, but my big prize to myself will be a new wardrobe at goal or under goal. So that's expensive enough! I have a history of holding myself to high standards though, so prizes at mini milestones are like "yeah well you should be doing this anyway so keep it up!" ha.