I'm having the same problem she is! I picked a halo for a cushion cut diamond and now I'm sure what kind of stone to pick. I'm having a hard time understanding the differences....
Ok - picking stone material or antique vs. modern cushion?
Asha is CZ core with diamond coating. It has been known to scratch and that bothers some people. BUT it isn't *that* expensive to replace every 5-10 years
You could search for longevity throughout the forum
Moissanite is a harder material than Asha; unenhanced is a "warmer" stone and some people like that. Amora Enhanced, I have heard, looks very diamond like and depending on the size can appear the same colors as the Asha.
Diamond is, well, diamond and has its own pros and cons.
A modern cut cushion has more straight line facets. An antique cushion has "chunkier" facets.
The Asscher cut is a modern-looking, architectural kinda stone. It has step facets (like and emerald cut) but in the shape of a square.
I think the Asscher really lends well to the tapered baguettes in the BTD setting. That kind of modern but classic elegance look. I like the "order" and clean lines of it.