A ramjet burns its fuel at subsonic speed, therefore at a higher temperature than a scramjet. At high supersonic/hypersonic speed that temperature let too much of the combustion products to be dissociated. This reduces the energy available for the exhaust gasses, that were already at subsonic speed, to be accelerated. So above a certain Mach number the scramjet will be more effective than the ramjet and at a somewhat higher mach number the ramjet ceases to produce thrust at all while the scramjet can go even faster. But nowadays that high speed is sometimes maintained by a scramjet only for some seconds. Patience.
I've been waiting for the Chinese to unveil a missile like this one. It didn't make sense, to me, that China would neglect exploiting the advantages that the P-700, P-800, Brahmos offers. I'm a long-time fan of the P-700 3M-45 Granat/SSN -19 Shipwreck missile and its derivatives. I think the best range for a missile of this type would be ~450 km/280 mi. For subs, that's a safe launch distance from CBGs and, for aircraft, it's outside the standard CAP radius. Of course, with the ~ 30' length and ~4500 kg weight this range would require, it would take one helluva aircraft to carry it.