User feel is often just a few timers. The documented per-user values all sit under HKCU\Control Panel\Desktop (and one Panel\Menus cousin) with plain defaults:
MenuShowDelay
ms before a menu opens on hover — default
400; 0 = immediateMouseHoverTime
hover timer used by listviews/menus — default
400DragFullWindows
1 shows contents while dragging; 0 shows only a frame — big difference on slow GPUsMinAnimate
1 = animate minimize/maximize; 0 instantWhy defaults are high
Defaults balance discoverability against input noise: a 400 ms menu delay prevents menus from popping when you sweep past heading toward a dialog. Lowering the delay trades that anti-noise for speed — measurable in any repeated-task session, imperceptible on machines where Remoting conditions made it higher.
The reversibility angle
Each value documents its stock default, which is why restore is a write, not a guess: put 400 back and the delay is exactly stock. That's the separating line between tuning and hacking: you can name what's normal before you deviate from it.
ProofTune ProjectEngineering notes — every claim here names the bytes a real tool touches. Verify first, install second.