I sound like a broken record, but I want no glorious new features, I want easy configuration for OS X clients - and not learn about arcane commands I need to give to Samba.
I've been having better luck with cifs when using OSX with a FreeNAS 9.10 server, but do still seem to have the occasional weird file locking problem.
When 10 came out, there was mention of a newer major version of Samba being included. I'm not sure what version is included in this 11.0 release, but if it's a major release or two higher than that in 9.10, then I'm kind of hoping it'll help.
That being said, upgrading my NAS isn't a high priority task. It's working "well enough" for now as is. :D