Rock solid may be a stretch. They still suffer from outrageous metadata bugs even to this day when used in busy file systems.
That bug alone has been open for over a decade. Development focus of the people who understand and want to fix those things have shifted to other filesystems like ext4 and ZFS.
From the top of my head, compared to ext4: RAM use and the ability to shrink an FS if necessary. Oh, also I’ve used an EXT FS driver on a Windows host, but I’ve never seen one for XFS.
Just to clarify, the previous comment asked about benefits of XFS over ext4. But I completely agree with your reasons for choosing ext4.