I noticed the following changes in Safari 15, compared to 14:

1. In Safari > Preferences > Passwords, the interface is different. If you want to view a password, you don't click the dots but simply hover the mouse over them. The password shows, but the background is dark, making it difficult to read (perhaps a security feature to make it harder for people looking over your shoulder?). Also, the Passwords preference window does not time out as it did in 14.

2. I have (actually, my wife) many pinned tabs. Opening several new, unpinned, tabs moves them aside so it is easier to see the tabs that are open. This solves an issue that I always had in 14. Of course, getting my wife to unpin tabs is slightly easier than achieving peace in the Middle East. The colors of the pinned tabs are brighter, making it easier to see them.

3. The open tab is now darkened, making it easier to determine which one is open.

Jon

macOS 11.7.10, iMac Retina 5K 27-inch, late 2014, 3.5 GHz Intel Core i5, 1 TB fusion drive, 16 GB RAM, Epson SureColor P600, Photoshop CC, Lightroom CC, MS Office 365