for what it's worth, XFS has had a lot of attention in the last 3 years or so.
when it was initially merged it had a _lot_ of SGI baggage (shim layers between the XFS code and the rest of the kernel). it has had a lot of cleanup and maintinance, including a lot of testing (and the development of a filesystem test suite that other filesystems are starting to adopt since they don't have anything as comprehensive)
so while I have been using XFS for about 7 years, I would not be surprised to hear that people had problems about 5 years ago. I would be surprised if those problems persisted to today.
personally, I don't trust Ext4 yet, it's just too new, and it's still finding corner cases that have problems. It also is not being tested against multi-disk arrays very much (the developers don't have that sort of hardware, so they test against what they have)