people like the canon t2i over the nikon d5100. even though the 5100 has an articulating screen, the t2i has 1080p30 AND 720p60, whcih is must more fluid slow motion because there are more frames/second.. the nikon only does 720p30 and 1080p30. the t3i has the articulatin screen. i havent heard anything about the t4i, i do prefer canon over nikon though. thats me personally.
sorry if my thoughts are a little discombobulated, im tired as hell. haha