First want to thank @cmcoker for tagging my thread which I hope provides some insight on how both the devices do certain tasks. I just posted this on my thread so I am just posting it here also, below were some of my observations when it comes just to the base unit itself
Apex has more features embedded into the HTML interface, accessible form any device that can open a web-page and does not require the use of a desktop app to configure. But will require you to use advance programming language when a function you want are not presented on the drop down menus.
GHL has more features not yet embedded into the HTML interface, and because of this require the use of a desktop app. When those features are converted to HTML the user will be able to program advance logic through those drop down menus as they can today through the GCC desktop app, never having to use a programming language and I believe we have access to more options because of what is already available within the desktop app. With some options within the P4 already their that require module to be added for the Apex to do the same task. (Ex. Flow monitoring, requires a FMM module to be installed for a Apex Unit but the P4 does this out of the box). Apex has some modules that GHL does not have for example WAV, COR, Radion control lighting. GHL has own LED lighting (LightBar, Simulation Bar and the LX series), Air/Humidity Sensors and Cooling fans.
Both devices have advantages and disadvantages and will control and monitor your tank, the good thing is we have great forum here and people that are knowledgeable about both devices, that can and will assist on issues or questions on either device.
My choice was based on stability, an expensive lesson for me to learn on the importance of stability, I have no regrets doing the switch from Apex to GHL. Their are posts of GHL to Apex, and Apex to GHL, my hope was to allow people to see the difference of how both units operate so they can decide which way to go.
WOW @Ditto !!!
This is an absolutely awesome comparison. Exactly the kind of information I was looking for. Thank You for sharing this.