Congratulations. I have the 650 as well and love it. Definitely recommend a set of grill grates. They make them for the 650 to lay on top and easily add another 100-200 degrees. Puts an awesome sear on steaks and burgers. I flipped them upside down this weekend and made some killer burgers.
My lid isn't an issue, but I did add a felt gasket seal when I assembled mine. It works quite well. I was happy to have heard about that fix here on the forum
That tri-tip looks awesome. What temp and time did you go with?