12V incandescent lamps have a smaller filament than the 120V lamps.
Reflectors are almost always designed for a "point" source. Therefore
the smaller the filament the more effective and efficient the reflector
is. Giving smoother and more controled beams of light.

All that said, make sure you have lots of uncontroled light in your
kitchen. Big, bright, open, cheery feelings are associated with well
distributed light, especially high on the walls and on the ceiling.

Intimate, small and dramatic feeling are associated with pools of
bright light and lots of dark corners.

RickR