The Leica M-E has a better sensor type than most cameras of this age and spec. This camera has a CCD sensor type, whereas most MILC digital cameras that came out around the same time as it have a MOS sensor type. CCD sensors produce high quality, low-noise images but consume a lot more power than CMOS sensors. CCD is the most common image sensor type used in digital cameras.
A CCD sensor type is actually the best sensor type across all cameras of a comparable type and age to the M-E.
The worst sensor type amongst comparable types of digital camera is MOS.