I will first address the remake issue, since it is the most poignant. No matter what word is used to describe them (remake, reboot, reimagining, etc), there are always people out there that would consider it sacrilegious that studios are even considering “replacing” their precious film. This is especially true with this film, since the original 1951 film is arguably the most beloved of classic science fiction films.
Well I have to say that I am spared from doing any comparisons, since I haven’t seen the original (as my Halloween thoughts from last year demonstrated, I definitely can be a person that prefers the original). However, I was most definitely familiar with imagery from the original, such as the robot GORT. As such, it definitely gave me chills when GORT made his first appearance in the film (especially on the huge IMAX screen I saw it on).
As for Keanu Reeves, he seems to get criticism for seemingly only having one emotion, but you have to agree that makes him perfect to play the alien Klaatu and I thought he was actually quite effective in the role.
In the end, I am judging the film not as a remake, but as science fiction film. As such, I thought that it was a pretty decent one.