NAS fro webserver content

has anyone had any experience with using a NAS device to store webserver content?

i have a client who has 3 webservers and they want to keep the data synchronized between them. using a NAS device as a single point for their data would do this.

Backup and disaster recovery not withstanding has anyone had any real world experience witht he speed of the NAS device and the speed of the websites it would serve?