I can recommend that version, I have been using 2.53 for a long time without bigger problems. But you should keep in mind that there will be no way back for your existing 2.49 User Profile after you will have used it with 2.53.2.
Additionally to the official Release Notes here you find some more information concerning changes with SeaMonkey 2.53.2
- Possible new bugs in SeaMonkey — only those with Status New or Assigned already have been confirmed as real bugs.
- Possible new bugs, caused by regressions in Firefox or in Thunderbird, which also might affect SeaMonkey. This query is not very reliable.
You can find workarounds for new problems in the Wiki
Download from here!
Please keep in mind, that download of Add-ons is (more or less) only possible with installed AMO Browsing for SeaMonkey 0.10.0. The name is misleading for historic reasons, the Add-on now works fine at addons.thunderbird.net. Unfortunately a related hint is missing in the Release Notes.
Thanks to all who contributed to the project and helped to make possible this release!