diff --git a/packages/react/src/internals/composite/list/CompositeList.tsx b/packages/react/src/internals/composite/list/CompositeList.tsx
index d1f47b79180..911a68c2bf3 100644
--- a/packages/react/src/internals/composite/list/CompositeList.tsx
+++ b/packages/react/src/internals/composite/list/CompositeList.tsx
@@ -297,6 +297,15 @@ function hasMovedNode(entries: MutationRecord[]) {
 }
 
 function sortByDocumentPosition(a: Element, b: Element) {
+  // Adjacent siblings are the common case for lists that are already in order, and
+  // `compareDocumentPosition` scans siblings from the parent's first child, so sorting
+  // a long flat list would otherwise be quadratic.
+  if (a.nextElementSibling === b) {
+    return -1;
+  }
+  if (b.nextElementSibling === a) {
+    return 1;
+  }
   // `DOCUMENT_POSITION_CONTAINED_BY` is always reported alongside `FOLLOWING`, and `CONTAINS`
   // alongside `PRECEDING`, so testing `FOLLOWING` alone orders siblings and nested items alike.
   return a.compareDocumentPosition(b) & Node.DOCUMENT_POSITION_FOLLOWING ? -1 : 1;
diff --git a/packages/react/src/menu/checkbox-item/MenuCheckboxItem.tsx b/packages/react/src/menu/checkbox-item/MenuCheckboxItem.tsx
index ce077dd01df..0b40e2787f0 100644
--- a/packages/react/src/menu/checkbox-item/MenuCheckboxItem.tsx
+++ b/packages/react/src/menu/checkbox-item/MenuCheckboxItem.tsx
@@ -10,7 +10,6 @@ import { useRenderElement } from '../../internals/useRenderElement';
 import { useBaseUiId } from '../../internals/useBaseUiId';
 import type { BaseUIComponentProps, NonNativeButtonProps } from '../../internals/types';
 import { itemMapping } from '../utils/stateAttributesMapping';
-import { useMenuPositionerContext } from '../positioner/MenuPositionerContext';
 import { createChangeEventDetails } from '../../internals/createBaseUIEventDetails';
 import { REASONS } from '../../internals/reasons';
 import type { MenuRoot } from '../root/MenuRoot';
@@ -41,13 +40,13 @@ export const MenuCheckboxItem = React.forwardRef(function MenuCheckboxItem(
   } = componentProps;
 
   const listItem = useCompositeListItem({ guess: true, label });
-  const menuPositionerContext = useMenuPositionerContext(true);
   const id = useBaseUiId(idProp);
 
   const { store } = useMenuRootContext();
   const rootDisabled = store.useState('disabled');
   const disabled = disabledProp || rootDisabled;
   const highlighted = store.useState('isActive', listItem.index);
+  const nodeId = store.useState('floatingNodeId');
   const itemProps = store.useState('itemProps');
 
   const [checked, setChecked] = useControlled({
@@ -64,7 +63,7 @@ export const MenuCheckboxItem = React.forwardRef(function MenuCheckboxItem(
     id,
     store,
     nativeButton,
-    nodeId: menuPositionerContext?.context.nodeId,
+    nodeId,
     itemMetadata: REGULAR_ITEM,
   });
 
diff --git a/packages/react/src/menu/item/MenuItem.tsx b/packages/react/src/menu/item/MenuItem.tsx
index 55f12663bd5..7d153a50072 100644
--- a/packages/react/src/menu/item/MenuItem.tsx
+++ b/packages/react/src/menu/item/MenuItem.tsx
@@ -6,7 +6,6 @@ import { useRenderElement } from '../../internals/useRenderElement';
 import { useBaseUiId } from '../../internals/useBaseUiId';
 import type { BaseUIComponentProps, NonNativeButtonProps } from '../../internals/types';
 import { useCompositeListItem } from '../../internals/composite/list/useCompositeListItem';
-import { useMenuPositionerContext } from '../positioner/MenuPositionerContext';
 
 /**
  * An individual interactive item in the menu.
@@ -31,13 +30,13 @@ export const MenuItem = React.forwardRef(function MenuItem(
   } = componentProps;
 
   const listItem = useCompositeListItem({ guess: true, label });
-  const menuPositionerContext = useMenuPositionerContext(true);
   const id = useBaseUiId(idProp);
 
   const { store } = useMenuRootContext();
   const rootDisabled = store.useState('disabled');
   const disabled = disabledProp || rootDisabled;
   const highlighted = store.useState('isActive', listItem.index);
+  const nodeId = store.useState('floatingNodeId');
   const itemProps = store.useState('itemProps');
 
   const { getItemProps, itemRef } = useMenuItem({
@@ -47,7 +46,7 @@ export const MenuItem = React.forwardRef(function MenuItem(
     id,
     store,
     nativeButton,
-    nodeId: menuPositionerContext?.context.nodeId,
+    nodeId,
     itemMetadata: REGULAR_ITEM,
   });
 
diff --git a/packages/react/src/menu/link-item/MenuLinkItem.tsx b/packages/react/src/menu/link-item/MenuLinkItem.tsx
index 3e426c3ac6a..4b4ea2c5587 100644
--- a/packages/react/src/menu/link-item/MenuLinkItem.tsx
+++ b/packages/react/src/menu/link-item/MenuLinkItem.tsx
@@ -5,7 +5,6 @@ import { useRenderElement } from '../../internals/useRenderElement';
 import { useBaseUiId } from '../../internals/useBaseUiId';
 import type { BaseUIComponentProps, HTMLProps } from '../../internals/types';
 import { useCompositeListItem } from '../../internals/composite/list/useCompositeListItem';
-import { useMenuPositionerContext } from '../positioner/MenuPositionerContext';
 import { useMenuItemCommonProps } from '../item/useMenuItemCommonProps';
 import { REGULAR_ITEM } from '../item/useMenuItem';
 import { useButton } from '../../internals/use-button';
@@ -34,13 +33,11 @@ export const MenuLinkItem = React.forwardRef(function MenuLinkItem(
   const linkRef = React.useRef<HTMLAnchorElement | null>(null);
 
   const listItem = useCompositeListItem({ guess: true, label });
-  const menuPositionerContext = useMenuPositionerContext(true);
-  const nodeId = menuPositionerContext?.context.nodeId;
-
   const id = useBaseUiId(idProp);
 
   const { store } = useMenuRootContext();
   const highlighted = store.useState('isActive', listItem.index);
+  const nodeId = store.useState('floatingNodeId');
   const itemProps = store.useState('itemProps');
   const typingRef = store.context.typingRef;
 
diff --git a/packages/react/src/menu/radio-item/MenuRadioItem.tsx b/packages/react/src/menu/radio-item/MenuRadioItem.tsx
index 044ead95926..724928410b8 100644
--- a/packages/react/src/menu/radio-item/MenuRadioItem.tsx
+++ b/packages/react/src/menu/radio-item/MenuRadioItem.tsx
@@ -10,7 +10,6 @@ import { MenuRadioItemContext } from './MenuRadioItemContext';
 import { itemMapping } from '../utils/stateAttributesMapping';
 import { useCompositeListItem } from '../../internals/composite/list/useCompositeListItem';
 import { REGULAR_ITEM, useMenuItem } from '../item/useMenuItem';
-import { useMenuPositionerContext } from '../positioner/MenuPositionerContext';
 import { createChangeEventDetails } from '../../internals/createBaseUIEventDetails';
 import { REASONS } from '../../internals/reasons';
 
@@ -38,11 +37,11 @@ export const MenuRadioItem = React.forwardRef(function MenuRadioItem(
   } = componentProps;
 
   const listItem = useCompositeListItem({ guess: true, label });
-  const menuPositionerContext = useMenuPositionerContext(true);
   const id = useBaseUiId(idProp);
 
   const { store } = useMenuRootContext();
   const highlighted = store.useState('isActive', listItem.index);
+  const nodeId = store.useState('floatingNodeId');
   const itemProps = store.useState('itemProps');
 
   const {
@@ -62,7 +61,7 @@ export const MenuRadioItem = React.forwardRef(function MenuRadioItem(
     id,
     store,
     nativeButton,
-    nodeId: menuPositionerContext?.context.nodeId,
+    nodeId,
     itemMetadata: REGULAR_ITEM,
   });