Couple points to consider:
- Your shared party wall will have batt insulation. And if they’re done properly you shouldn’t head your neighbor.
- The gypcrete topping isn’t required and doesn’t really assist much in sound other then it forced the builder to ensure there aren’t any holes in the floor before pouring (or else the topping drains/drips through said holes). Most developers aren’t using gypcrete topping so I’d say this is better then average.
- The biggest concern for sound will most likely be the corridor (sound will travel into your suite either under the entry door or through the mechanical system) and the unit above you. If you can get onto the top floor you’ll be much better off.
- Avoid the elevator core area. Look for something at the end of the hall (maybe adjacent to the stair core) which might not be used much.