Just finished watching Evangelion 3+1: Thrice Upon a Time, in fact I waited until all four Rebuild of Evangelion movies were released so I could watch them all.
The first two RoE movies are basically a retelling of the original series, a major difference being that the Angels are far more powerful and the battles are far more epic and destructive. However the climax of the second movie is where RoE wildly diverges from the original series.
In many ways RoE could be considered a counterpoint to the original series, as Shinji is a lot less mopey, the movies are far more action-packed and less psychological and the story ends on a hopeful note compared to The End of Evangelion which had a rather bleak ending.
Overall very enjoyable. The only character that left me puzzled was Mari.