Miltoniopsis are cool growers and Miltonia tend to be warmer growers. Miltoniopsis look more like colourful pansies, while Miltonia usually don't have that rounded look so they sort of look like an oncidium. I think the plants look very similar, but the blooms differ slightly. I don't really grow them so I hope I have it right. I just have one Miltonia that got dried up during my vaccation. If I happen to set up a shop light in a cool basement room then I might get some $10 Miltoniopsis.