I'm running the second leg of a 4x800 and the open 800 at my area's JV league championships tomorrow. My PR is 2:12 splitting 64-68. I intend to race both heats as hard as I can because it is my last meet of the season and I believe my team could win the relay.
I run about 35 mpw with weekly 8-10 mile long runs at 7:30 pace. I also do interval workouts once a week or so, usually 4-8x200s and/or 400s at 32-35 and 68-72. Predict my times if I go balls out in the relay and lay it all on the line in the open.