Just less than 60-degrees (28-29 degrees off the apparent wind); that was with crew in 12-15 knots of wind on flat waters. I haven't thought to actually measure the angle on the GPS (heat of the moment and all). I regularly tack 30-35 degrees off the wind.
There are many factors that come into play in determining how high a boat can point. Besides re-designing the boat, spending lots of money on new sails and gear, and having lots of "rail meat" in the right place; anything that causes drag and slows the boat down is really all you can control.
...Yep, narrow pointing angles are what J36s were made for. Well, that and speed.
J/36 "Zero Tolerance"