The Geforce GTX 470 gives a smoother impression. Although it doesn't offer the best framerate in the world or unmatched image quality, it nevertheless is able to stand up to the Radeon HD 5870. Depending on the individual test Nvidia's card is slightly faster or slower than HD 5870/1G. Furthermore the GTX 470 reaches, with 3.7 Sone, about the same noise level as the default design of the Radeon. But of course there are custom designs of the HD 5870, like Sapphire's HD 5870 Vapor-X or the Powercolor Radeon HD 5870 PCS+, which are only halve as loud. The GTX 470 nevertheless seems to be the better overall package than the GTX 480, especially if you take a look at the 30 watt idle power consumption (although this is still 50 percent higher than the power consumption of the Radeon HD 5870).
Radeon HD 5870 or Geforce GTX 400? The Radeon's advantages are the lower power consumption, the custom cooling solutions, as well as the optional Sparse Grid Supersampling Anti-Aliasing. The Geforce on the other hand offers the better Anisotropic Filtering, CUDA respectively GPU Physx as well as the higher Tessellation performance and, in case of the GTX 480, better fps results.