Fear Itself is great stuff! Some episodes are better than others but that's true of any series. I just wish we had more horror series like this on TV. There seems to be a fairly wide range of directorial and writing styles (and even acting abilities and experience) in comparing episodes, but that's certainly not a problem for me. And Fear Itself has plenty of style.
In my humble opinion, foibles not withstanding, Fear Itself can take its rightful place with Twilight Zone, Night Gallery, Outer Limits, Night Visions, Supernatural, etc. as some of the best the horror genre has to offer.