Mostly positive review from Engadget. Gives high marks to performance and especially the display. The Verge gave it a 9.0 and c|net gave it an "editors choice". Will be interesting to read if forum member reviews are similar.
http://www.engadget.com/2012/12/03/apple-imac-review-2012/#continued
http://www.engadget.com/2012/12/03/apple-imac-review-2012/#continued