Is there any difference between the features or functionality of DxO ViewPoint and Nik Perspective?

This information applies to version(s): 3, 4

DxO ViewPoint 4 offers additional features which are not included in Nik Perspective: ReShape, Flipping images, automatic preview (standalone version only) and Guidelines (standalone version only.

There are no differences between DxO ViewPoint 3 and Nik Perspective in terms of functions or features. The unique advantage of DxO ViewPoint is its ability to be used seamlessly as a plugin within DxO PhotoLab, whereas the extra benefit of Nik Perspective is that it can be installed alongside the other Nik plugins, making Nik Collection a truly comprehensive suite of plugins.