Canon 60D is NOT weather sealed based on a lot of professional reviews, it is a better camera in terms of having a faster shutter speed, filtering (built in), built in focus motor, level finder, and few more of less important perks in comparison to T4i (great camera), if money is not the issue I personally would prefer 60D but if you are not in a rush and can wait for few more months (do NOT buy first batch of cameras released!) you might be getting a better camera as 70D should deliver more in terms of image quality and futures.
I've almost picked up 60D buy after a longer research decided to give it a pass, especially after seeing image comparison between Iphone and 60D quality of pictures where ... IPhone was better
better in low light? source?