Personally, if space and mobility is not an issue, I’d consider ease of maintenance, long range cost, weight, upgrade-ability, etc, etc. If these turn out to be even as well, I always go with a product with a warranty.
As for water additives, there are a few out there, which if I understand correctly, just break down the water surface tension. “water wetter” and “purple ice” are two that I’ve heard of,…. I’m running water wetter.