When comparing CDNify vs Whipper, the Slant community recommends Whipper for most people. In the question“What are the best CD rippers for UNIX-like systems?” Whipper is ranked 13th while CDNify is ranked 15th. The most important reason people chose Whipper is:
It might be the only secure ripper for GNU/Linux that's in active development besides Rubyripper as of 2019.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Actively developped
It might be the only secure ripper for GNU/Linux that's in active development besides Rubyripper as of 2019.
Pro Most features
(of any secure ripper on Linux so far (2019))
Cons
Con Might refuse service if it can't access impeccable metadata for your disc
Must use --unknown flag if ripping a CD which doesn't have a matching TOC in the MusicBrainz database.
Con No graphical user interface
As of 2019 there is no GUI available yet, so some users may be repelled or have a steep learning curve. If you can't do without a GUI you may want to give the somewhat more limited Rubyripper a try.