Hi there, I'm still here! I have some NOTD photos and a product review waiting in the wings but I wanted to post these comparison photos today because they're ready to go.
1. Sally Hansen Prisms Ruby Diamond
2. Sally Hansen Prisms Golden Tourmaline
3. Hits Ares
4. Ozotic 511
5. Catherine Arley 800
6. OPI DS Reflection
Numbers 1 through 4 are linear holos; 5 and 6 are holo sparkles. I've been in search of a true red holo for a while now, and while Ozotic 511 is gorgeous I suppose I really meant to order 621 (and uh...probably will at some point!). Glitter Gal also has a gorgeous red. I bought Ares - the red from the Brazilian-based Hits No Olimpo collection - because there were a few I wanted to try anyway (and I will post about them at some point soon).
Here they are in more direct sunlight.
Here's a full swatch of the Catherine Arley.
Anyway, if you've been looking for a red holo or holo sparkle - hope that helps!