While I'm sure the dock brings its own set of problems and complications, I can confirm that I have been battling the "crash during sleep" issue on two Surface Books and I don't have a Surface dock.
As widely reported here and other forums, it seems to be related to a period of time after it sleeps. Switching everything to hibernate only seems to fix the issue, so its somewhere between connected standby and a deeper sleep state that the issue happens. Looking at event logs usually shows one or more DistributedCOM errors prior to a kernel-power, sometimes a BTHub error. My thinking is this is still related to applications and / or drivers failing to behave with connected standby. Perhaps more specifically the changes made to connected standby after the February update.