When comparing Mastodon vs Gajim, the Slant community recommends Mastodon for most people. In the question“What are the best XMPP clients for Windows?” Mastodon is ranked 4th while Gajim is ranked 6th. The most important reason people chose Mastodon is:
Ranked in these QuestionsQuestion Ranking
Pro Social publishing
Pro Actively developed
Pro Jabber Texting
Pro Open Standard
Pro Open Source
Pro OMEMO encryption available as a plug-in
Con Lacks OMEMO encryption
The de facto standard for Jabber Texting [xmpp].
Con Chat logs are in SQLite DB.
Plaintext (or XML/markup) logs are not available.
Con OMEMO not natively supported
Con Chat logging enabled by default
Problematic for encrypted chats.