You do have to stay within the same vendor to get the very high level of control and monitoring. Hardware monitoring is also a place Mac does better, as Apple knows all the hardware it can be running on, and has designed that hardware to allow monitoring. On the server end, the XServe has over 100 hardware monitors, all processed by a dedicated chip and remotely viewable even if the OS won't boot (Remote Desktop will work in that case too). Very good LOM. Oh yeah, the remote monitoring software for the whole network (hundreds of servers) is included.
What do you consider "very high level"? I'd consider the idea of trying to manage a Windows network of any appreciable size without AD and group policy to be insanity, not inconvenience.