You can't generalise this with the Grandinote speakers. They are not exact high efficiency because you are not running them with 45, 46, 2a3, GM70, etc. You are running them with Jadis and Gryphon.
But they respond better to gryphon? Will listen to the video tomorrow. If you are finding that Gryphon drives them better than Jadis, it just means they need that grunt. The Grandinote amp too seemed to have an advantage over them in control