I just bought an Apex and a trident. I barely have the apex running, but I love it so far.
Just a warning, it gets expensive fast to get it to do everything you want it to do. Before you buy, figure out how many outlets you want to control / monitor. You might need a second one of their power strips.
The only stuff I could think of getting before an apex might be a second return pump to have on hand as a spare or to run in tandem as a backup. I bought two S2’s over a single M2 for that reason.
Maybe also consider an inverter/charger and a few batteries or a generator to mitigate an extended loss of electricity?
I often spend a month or more away from my tank and an apex and some webcams are a part of that plan. I feel very confident that I can leave my tank and be just fine.