I have been having a nightmare of a time trying to open DNG files in Aperture 3 (trial version) and I'm wondering whether to just give up on it in favour of Lightroom or Photoshop. The raw files ...

It supports various raw image formats, such as ARW (Sony), NEF (Nikon), CR2 (Canon), and DNG (Adobe). You can preview photos before recovering them – an added benefit.