From my understanding via searching on
Amazon (could be totally wrong based on incorrect descriptions). Also in order of price High to Low
MCP - Wifi controllable with LCD controller and smart detection upon dry detection - $$$
ECP - Wifi controllable with LCD controller - $$
SCP "M" - Wifi controllable with analog controller - $$
SCP - Non-Wifi controllable with analog controller- $
DCW - Can't find anything on this one.
Current
Amazon prices and flow rates per
Amazon (take it with a grain of salt) for -150 variant:
MCP-150 (6000-7500GPH) = $125.98
ECP-150M (5283GPH) = $123.99
SCP-150M (6000-7500GPH) = $122.98
SCP -150 (6000-7500GPH) = $110.99
Seems like minor differences in wifi connectivity and the type of controller. I personally prefer to keep these particular devices of foreign origin off of my wifi, could be excessive paranoia, but I also have a large number of devices on my network as-is. I do think having the dry detection feature is nice, if it works as advertised. Certainly wouldn't rely on it everyday, but good failsafe for an extra $15. SCP has pretty straight forward controls so I don't know what the LCD controller provides in terms of user experience. My 2cents