The performance of a floor is matter of opinion.  The “feel” that satisfies one individual may not satisfy another.  Many factors affect the perceived performance of a floor. They include:

The joist depth

The stiffness of a floor can be markedly improved by increasing joist depth.  For example, a 25% increase in joist depth will double the floor stiffness.

The joist spacing

The stiffness of a floor increases in proportion to reductions in joist spacing.

Continuous or simple spans

Allowing joists to span over internal load-bearing walls instead of breaking them at these points can increase floor stiffness by up to 240%.

The decking / flooring material

Thicker decking slightly improves floor performance – 22mm chipboard increases floor stiffness by approximately 2% compared to 18mm chipboard and means less ‘local’  deflection under foot.

The fixing of decking material to the joist

Gluing the floor deck to the joists significantly improves floor stiffness, by as much as 70%.

The ceiling material below the joist

Directly applied ceiling boards can improve floor performance by up to 3%.

Level bearings

Unlevel bearings can mean joists feel "springy" under foot near bearing positions.

The location of walls and furniture

The position and size of dead loads on floors can either dampen or exaggerate the dynamic response of floors under foot.