IIRC KMC and shimano 10s chains I have measured have been identical widths (as per spec) but a couple of SRAM 10s chains I have measured recently have been a fraction wider than that (and wider than a 10s chain should be, not far short of some 9s chains in fact). The SRAM chains ran noisy and rubbed the plating off adjacent sprockets in a SRAM 10s cassette.
cheers
