Actually, if you were mad enough to use the feature, the Dec10 had 6-bit "bytes" - 6 to a word.

Anyway, I do not see how this affects the design of C in a way that makes no sense anymore today (except that one could require CHAR_BIT to be eight, but there are still DSPs where this is not the case). I think people repeat the "the C design reflects the out-dated PDP-11 hardware" meme because it sounds smart while in reality it is just nonsense.

On the 11, the UNIBUS was 18 bit, the program space was 16 bit, and addressing was 22 bit. So it depended if you were using I-space or D-space.