The recently released 24 Megapixel Canon EOS 760D ( Rebel T6s ) & EOS 750D ( Rebel T6i ) have quality control issue. About 4 out of 10 EOS 760D and 2 out of 10 EOS 750D have dust like spots all over the sensor. Users of affected units might notice the issues at high aperture, since at wide open aperture most sensor issues are masked. The problem has been explained by Roger Cicala at LensRental.
The problem has been reported to Canon. And they are investigating the issue very seriously.
You can read the full report Here at LensRentals