Hello,
Here is what I know,

1. Fences 3 has stop major development for sometimes now, and only Fences 5 still actively developing. And if you keep on Windows 10 or 11 updates to its latest version. Fences 5, is the best bet to ensure compatibility.
2. If you have multi-monitor setup, it is best to have Fences 5. Fences 5 recently introduced all new Layout Engine to resolved multi-monitors issues.
3. Fences introduced peek function in Fences 4, this will allow user to bring Fences on top" of all other opened Windows. Fences 5 needed for current Windows 11 v24H2 for peek to work properly.
4. To know more on how far Fences 5 has come since Fences 3, please visit Fences History Changelog: https://www.stardock.com/products/fences/history

Yes, as suggested by Doc above, please try the 30days trial and see if Fences 5 is for you.

Thank you,
Basj,
Stardock Community Assistant.

Great, glad to hear that, if you have any issue on Multiple monitors setup. Not that you will, but, we often get reports from peoples who were upgrading from older Fences version. Please refer to this post and try the troubleshooting guide in the first post: https://forums.stardock.com/528229/.

Thank you,

Basj,
Stardock Community Assistant

Possibly the only time you might stay with Fences 3 is if you are a dinosaur like me and still running Windows 7.  Both are contemporaries so well suited.  I have no real reason to move to 5, however all the other systems are on Fences 5 [and Windows 10] ...