I bought the apex with the standard ph probe and then the leak detector, fish feeder, breakout box and a second eb8. The fish feeder is ok, and there is another one that looks like the same product just without apex controllability for 59.99 on bulk reef supply. Everything else is awesome though, just not all the impressed with the feeder. Connecting to fusion is a SNAP, I thought it would be way harder than it was. The same applies for text messaging, super easy just a few clicks of a menu. I had an aqua controller III for ph control (calcium reactor) and a reliable timer but I wanted something more to meet my needs.
I will be traveling a lot so the leak detector, customer service (usually respond within 2-3 hours by email), alarms, and stability sold me. The gold has the PM2 with salinity probe which I really want but was spending a grand on what I already had lol and I feel like I will end up an ORP probe just for the sake of monitoring everything. The second eb8 is so useful so I can control every single pump and light on my tank, especially useful for maintenance and fallback plans. Such as secondary heaters and pumps.
Now to your question, you have quality equipment so why invest? I have to say that its failure protection and warning, somewhat like life alert for your tank, in a way. I have had heaters fail on me and toast my fish, pumps die, sumps overflow, stray voltage (that one really sucks, a sudden shock when you go frag a coral). Like I said I will be traveling a lot and my tank is on the 2nd floor, so I need to know when there is any amount of water on the floor so that I can act accordingly and not come home to an saltwater flood.
Some of the equipment we buy is not self monitoring, which is very much ok, but if you want to know things like when your ATO chamber gets low then I would say get the breakout box and a madison 8000 float switch and make a hanger out of acrylic (took me 15 minutes to make and setup). My system texts me when the ATO is low so I do not have to check it every night and although the feeder is really more of a gimmick, I am glad I finally have one.
Basically it tends to the tank and lets you know when you may need to do something. Yet another way of thinking about it is would you like to cut out some of those monotonous routines such as ATO checking, checking the tanks temp, checking for leaks, shutting equipment off for maintenance and feeding. I was spending a lot of time doing those things and had much more important things to do. Also slightly off topic but I also bought the finnex titanium heater and am very happy with it.