I've used both picosleep on a non-w pico for awhile now, works great! But I'm running into an issue with the pico w. If you start up the wifi:

wlan = network.WLAN(network.STA_IF)
wlan.active(True)

Past this point I believe there is currently no way to turn off the pico W RF antenna.

wlan.disconnect()
wlan.active(False)

Does nothing. After starting wifi, that 1.5mA during sleep jumps to 2.2mA during machine.lightsleep() and picosleep(). No it's not insane, but if I could get mA back down to 1.5, I could gain 20 days of usage.

I don't know if people make use of keeping the rf on during sleep periods. Id assume if one is truly chasing efficency theyd want to have their current draw during sleep periods be as low as possible, and then restart the antenna after. I figure this is a nice way to make picosleep more useful then machine.lightsleep. I really don't know how hard this would be to implement, but I figure I'd bring it to your attention.

Thanks