NFS is a gruesome mess when files aren't exclusively used by a single client (namespace and time(!). A lot of "classic unix" ideas are very, very bad ideas on NFS and will either not work at all (good) or silently sometimes randomly discard data (juck).
NFSv4(.1) was largely created to fix this. It has delegations, a mechanism for clients to have coherent caches and exclusivity when needed. As far as I know it works just fine, the world just mostly moved away from wanting NFS.
