NVIDIA released GeForce Experience 1.8 update which adds microphone recording support for ShadowPlay, reduces video stuttering and removes 1080p re-scalling. See below for full changelog.

GeForce Experience

Changelog:

Optimal Settings

  • New optimal settings slider adds fine grained control over performance and quality tradeoff
  • Ability to select and optimize for different resolutions
  • Ability to select Windowed, Full-screen, or Windowed Borderless modes.
ShadowPlay
  • Removes 3.8GB file limitation in Win7.
    • Record up to 20 minutes in Shadow Mode
    • Unlimited recording in Manual Mode
    • ShadowPlay creates new files once 3.8GB is reached
  • Captures video without re-scaling at up to 1080p. At higher resolutions, aspect ratio is preserved.
  • Adds microphone recording
  • Captures video at 60 fps instead of 62 fps
  • Reduces stuttering in captured video
Other Improvements
  • NVIDIA "UpdatusUser" user account is no longer required for installation
  • Adds ability to scan for games in folders and network drivers with user read-only permissions

Download NVIDIA GeForce Experience 1.8 here.