At the sensor level it's not like there's a lot of data available to the bottom five or six stops of the DR anyway. Given that the sensor is linear, the first five stops covers the range 0 to 32, of a total of 16384 levels. When you look at where the mid tone is actually situated, at -3 stops from saturation. That gives a mid tone value of 2048. I'm not sure what level of noise is inherent in either the Sony or Canon sensors, but even if it means that you have a difference of two stops, say bit 5 for Sony and bit 7 for Canon, that actually only amounts to a total of 96 extra levels that you can record at the sensor.
Personally I would rather have my exposure sitting at the righthand side of the histogram. That last stop of light gets a whole 8092 levels to describe it. So there is far more information in the higher bit values of a linear sensor. The real problem is that with a digital sensor you have a hard upper limit, there is no signal roll off, like you get with film, or even at the other end of the digital range.