[CentOS] ext4 in CentOS 5.6?

I'm sure many are running ext4 FS's in production, but just want to be
re-assured that there are not currently any major issues before
starting a new project that looks like it will be using ext4.

I've previously been using xfs but the software for this project
requires ext3/ext4.

I'm always very cautious before jumping onto a new FS, (new in the
sense it is officially supported now)

Thanks in advance!