I use both in some applications. The sealant gives a very high gloss 'hard' glassy looking shine, the wax softens that somewhat and makes for a richer and warmer look. While wax is the look I prefer on those paints from a protection standpoint the wax on it's own doesn't provide the lasting protection the acrylic does, 8 weeks vs 8-12 months.
The Klasse isn't a wax, it is an acrylic sealant. It really lasts and from a price standpoint that makes it well worth it. Even though there are less expensive alternatives, in my experience since they don't hold up as well they end up costing more in both $ and labor due to having to repeat their application. Waxes don't hold a candle to sealants in terms of staying power.