After owning a Digital Aquatics RKL for quite a few years, i've recently made the jump to an Apex.
I haven't even had the chance to fully set it up yet, but from what Ive done so far, I can say the Fusion software is the controller interface I wish existed years ago. Now... I did just turn 30 years old this year and have never owned an Apex, so following along with the instructions for setting up a new account and linking to my new controller to my wifi wasn't too difficult for me but It does have some confusing moments where you kinda feel like your going in circles clicking links to set things up. BUT if you don't overthink the process (or get distracted like I did) its actually relatively easy.
If I was helping my father with this Id tell him to have his wifi password handy as he never remembers it. Final advice.... All that said, there really probably aren't any easier options out there and going less expensive usually means "out dated" and "no longer supported" much more quickly. Neptune makes promises of continuing back compatibility but from my experience, in general, I wouldn't recommend buying equipment that is being "phased out." Just my two cents.