I would have to A/B them in person. I heard the Everse once, and the only thing I could determine was that it had more bottom end thump over the Bose S1 at normal sound volumes, but did not think it had a sonically better sound than the S1. The Everse is worth it for all the newer additional features though.
One thing you lose if you even consider it any kind of an issue is it is slightly taller speaker, and weighs a bit more. So slightly less portable, and if you are transporting the speaker in a tight nook type space in your vehicle, the Everse may not fit as good as the Bose. For example. when I am bringing multiple sound systems, lighting etc. I fit TWO Bose S1 Pros standing up under my dash boand and in front of my front passenger seat in my Chevy Traverse along with my laptops bag behind them on the floor. If the S1s were like 3-4 inches taller, I could not fit two of them in that area. Only 1 could be fit laying down on it's side in that scenario.