Aside from the lack of an optical out, you won't miss the original PS4.
PS4 Slim review: A smaller, sexier console with few compromises
Sennheiser EPOS GAME ONE Open Acoustic Gaming
PS4 Slim: A smaller, sexier console with surprisingly few
Xbox Series X 1TB Console with Additional Controller
Digital Foundry: Hands-on with the CUH-2000 PS4 Slim
PS4 Slim revealed: A smaller, sexier console with few comprimises
PlayStation 4 Slim review: Wait for the PS4 Pro if you can
Sony PS4 Slim review
PS4 Slim review: A smaller, sexier console with few compromises
PlayStation 4 Slim Review: The Default Choice
Digital Foundry: Hands-on with the CUH-2000 PS4 Slim