At least the Linux NFS client made some big improvements in stability by the mid-2000s. FreeBSD took longer but I've heard they've fixed the kernel deadlocks as well.

The other interesting note is that they apparently only support NFSv4, which has some welcome improvements: it uses TCP over a single port, avoids the entire portmap/statd/lockd train-wreck, UTF-8 everywhere, etc. One of the more interesting ones is that it has referrals (think HTTP redirect) so one server doesn't have to handle every request from every client and you can do things like load-balancing. Clients are also assumed to be smarter so e.g. local caching is safe because the server can notify you about changes to open files rather than requiring the client to poll.