Yep... I have both... Dorco cartridge style/Mach 3 clones.... and Dorko straight razors.

I still use the cartridge style to shave my head and, what impressed me anout the Dorco cartridges was longevity... I get about 4-5 months out of a single cartridge shaving my head 1-2 times/weekly and that is a lot of skin real-estate! So, my $40 bulk purchase of Dorco handles/cartridges looks to last me a few years easily.

But, the one thing I do notice is razor burn (slight) on my head whereas zero on my face with SR's!