I have both installed on my phone.
I like the cleaner interface of Energi, but I like the detail that Remote S gives you (ex. I love being able to see how much energy, total, it has taken to charge my car).
I think the interface to Remote S is too cluttered to use as a daily app but, again, it's good for details. Energi is good for quick info, plus I like that there's an included list of chargers sorted by distance from your location.
Energi has a watch complication that allows you to see your battery percentage, where Remote S only has an app.
Those are my top 3 comparisons.