I have my 2 tanks connected to my Apex, it makes my life easy. It's been running 5 years now without any hiccups and has saved me a number of times.
All I "use" it for is dosing, heat, refugium light, and leak detection. My powerheads, return, skimmer, and tank lights are all plugged in but aren't controlled by the Apex as they are always on.
I would never run it without a controller now, especially with detecting heat and leaks, and the simplicity when I need to turn certain things off while cleaning the tank.
With the new version out, I'm sure you'll be able to find a used one for a bit cheaper now, scour the forms and see what you can find.