Chris, the switched AC lead would work just as well in the field. In actual use I found all that the extra switch added was an extra switch to operate without actually providing any benefit. Once you turn off the AC then the PSU is off anyway!
I've had the DPS-600PB setup for years any it's never missed a beat, definitely a fantastic and dirt cheap solution. I ended up having to upgrade though as it wasnt enough to power my iCharger 4010 duo, even trippling them up for 36V would have still been a bit short of power so i got a HP ESP-120 that knocks out 2950W... But it's MASSIVE! I still use the DPS-600PD set for my smaller charger.