I’ve been using the Steamdeck with Xreal glasses (1080p 60hz) since the release and can confirm the AMD 13 with Nreal glasses is a solid upgrade. I was getting MUCH BETTER graphics and frame rates while playing Warhammer: darktides, or Cyberpunk 2077.
The 7840U is a solid upgrade over the steamdeck along with egpu support. If you don’t need a handheld but want to game it’s a no brainer.