WaveLab can also be used as an external audio editor in Cubase or Nuendo. However, you can produce in Nuendo and then send the file to WaveLab for mastering. You can master in a DAW, but it is a different workflow than mastering in WaveLab, and if you need to create DDPs, I'm pretty sure Cubase and even Nuendo do not accomplish that. You cannot really use one in place of the other. Nuendo and WaveLab Pro are more complimentary than competitive. It has a design focus on Mastering and Restoration, and has track-level spectral editing and is also a destructive wave editor - on top of all the production features. The only DAW that is somewhat comparable to WaveLab Pro is Samplitude Pro X Suite.

It is used for Audio Restoration, as well. It's also an advanced Audio Editior (Non-Destructive Montage and Destructive Waveform Editor), which also does Spectral Editing. Not just single tracks, but full albums, etc. It is more similar to Adobe Audition, with a much bigger emphasis on Audio Mastering. WaveLab is a Mastering DAW and advanced Audio Editing Application. Nuendo is to Cubase what Pro Tools | Ultimate is to Pro Tools, or what Sequoia is to Samplitude Pro X. Nuendo is Cubase Pro with features for Sound Design (Game Audio, Post Production), Film Workfows, and Broadcast.

Sound forge pro suite vs wavelab pro