Well, there's something we can agree on, at least.

I spent several hours debugging some very complex software, a few weeks ago (I was porting some cross-platform code to OS X), trying to figure out why I kept getting blocks of zeros in a file I was trying to read on Lion. We have a multi-threaded asynchronous file system abstraction layer, plus a couple layers of buffering, plus our own memory management model, all of which, at different times, have caused similar symptoms due to various corner cases. Turns out it's their CIFS mount client. WTF? Working fine on 10.6, jettisoned, and completely broken for Lion. I'd have been fired for putting something that broken into production software. Steaming turd, indeed.