Where the weight is (Moment of Inertia) makes a difference in handling. Typically not felt sitting, but felt standing.
Moving the same weights apart evenly maintaining balance is changing the moment and the handling.

Components/groups do not remove weight equally from all parts. A $500 more expensive bike with the same groupo (this thread) will often lighten the seat and post and bars and stem. If you are lucky the wheels and tires. That is weight that can be felt - even if you re-add that same weight to the middle of the frame.

My advice was go with the extra $500 bike assuming that $500 went into better parts.