Some argue that it is pointless to use Leica lenses on DSLR's, since their super-high resolution is lost on low-resolution sensors. A 120 lp/mm Leica lens seems to them like overkill for most conventional DSLR ,which can barely reach 40-50 lp/mm .
This is not so for Sigma cameras!! Serious studies on Foveon sensor capabilities report, that , even though their Spatial Sampling Frequency ( Pixel Spacing) is 127.53 pixels / mm , their EFFECTIVE resolution reaches 132 pixels PER MM , that is far above its Nyquist frequency (1/2*pixel spacing) , with no limiting Moire.
This is the kind of resolving power Leica lenses are famous for.
A match made in Heaven.