Yes, the SO thread is where I saw the WG GMOP bracelet! I am trying to decide on my next set (e.g. 20 motif, VA earrings, 5 motif bracelet). The WG GMOP is really beautiful and iridescent, but you are correct, I've been comparing it to WG oynx and the oynx has more punch. I already received the SO price for the oynx set, but I did not yet purchase as I was worried it would be too much black againt the face (e.g. earrings, necklace) and I also wanted to maybe add in the Cosmo oynx. Then I saw the WG GMOP bracelet and thought.. wow... maybe GMOP!
I would love to see it side by side, and even better next to WG MOP in case I plan to wear the two 20 motifs together (MOP & onyx or MOP & GMOP).
I actually tried on the oynx/pave 20 motif. I actually thought that would be the perfect balance, but I felt as a 20 motif, it was too "airy", and I wanted the punch of 20 evenly spaced oynx stones on a long necklace. That's just me, the oynx/pave is a gorgeous necklace.
I had not thought about an all WG 20 motif, but that's an idea too. I don't ever recall seeing it as a bracelet. WG in Alhambra is very limited as you know. Everytime you ask for a stone combo in WG, it's no no no.

(makes you want to give up and move on to another brand). I hope they come out with more WG options next season.
If you are considering a SO, the SO prices I received for the oynx set was not too bad. I would expect the GMOP and hammered WG will be roughly the same.