I haven't noticed poor wake times, but my laptop does kernel panic and reboot a fair amount. Maybe 4 times in the past week. My hunch is that it's Spotify's fault but I haven't dug into the logs.
xnu will panic if it doesn't receive periodic check-ins from userspace. For example if WindowServer hangs, then the kernel may deliberately panic so that the system reboots. See man watchdogd for (a tiny bit) more.
I have this problem but only if I've been plugged into a monitor, and then unplugged and gone onto battery. Rebooting after unplugging stops it but its annoying.
I've had mine panic and reboot twice, both times happened shortly after disconnecting other Macs that were connected via a Thunderbolt cable (target disk mode).