We are using NEO in TargetProcess project. So far so good in general. Simple operations with database are really simple, code looks much more better, unit tests are clearer and faster to write. Yes, unit tests are really fast. NEO provides database abstraction in its core, and real database is not required for tests. I like that.
But there is one nasty bug I had not fixed yet. Sometimes NEO throws an exception when trying to cast objects. The problem is very strange in fact. I did not dig into details, maybe it can be fixed within reasonable time frame. Anyway, this bug worsens overall (good) impression.