It's hard to imagine that fans of Evangelion won't be pleased with this leaner, gorgeous rebuild of the original anime series. And if you're new to Evangelion, this is a great place to start.
You Are (Not) Alone is a pretty straightforward adaptation of the first six episodes of Evangelion. It's somewhat condensed but still containing all the major moments and plot points. While the next three movies promise new story additions and characters, this movie contents itself with mostly cosmetic changes, along with tightening up the story, a few extra scenes, and eliminating some filler. There wasn't a lot in the first six episodes that needed to be altered.
That means slightly less whining from Shinji. SLIGHTLY.
The animation and visuals are outright beautiful, especially on blu-ray. I could recommend this on that aspect, alone. The re-designed Angels and action scenes are improvements over the original's (especially the sixth Angel), in my opinion and the voice work is great.
Does You Are (Not) Alone make the original series redundant and unnecessary (or vice-versa)? No, I don't think so. Both of them have merit, and both are worth watching. But, I'm very interested in seeing if the next three Rebuild of Evangelion movies rectify some of the mistakes that the latter portion of the series fell prey to.