The funny part if your question is "what is the truth?" The truth probably won't be found here. Instead, you'll get opinions... It's my opinion that they are virtually the same. As are cinnamon and black pastel; mystic/phantom; yellow belly/goblin; nazca/sentinel/paint; lemon pastel/pastel; coral glow/banana...
It ends up being comical to me. Arguments are made saying that one has more blushing than another. One has different yellows than the other--whatever subtle differences are claimed. But the same things are pointed out on normals, and people are told it's just a pretty normal. I've seen mojaves that range from dark gray to faded almost silver, but they're still mojaves. I've seen busy patterned normals, reduced patterned normals, light normals, dark normals, yellowish normals, pied marker normals, etc. if normals can vary so widely, then why can't a lesser? When can we finally call butters and lessers either only butters or only lessers? If cinnamons throw lighter supers than black pastels, then explain Steve at Serpents Den's really dark super cinny.
Pieds vary widely, too. They can be 90% white, or 10% white they're still pieds. If someone else produced their own line of pied, and it produced mainly 25% white pieds, would we call them something else?
So, after my little soap box, back to the original question... I think calicos=sugars and lessers=butters, etc.