I totally agree with you. For somewhat different reasons, I feel like for a pave necklace is best without guilloche even though it is gorgeous. My personal reason is that if I invest in this piece, I want to be able to wear it freely; layer it with others, toss it in my handbag for later, not worrying about any wear and tear; no situations where I do not wear it because of weather or potential for damage. I personally love alternating pave and hammered and alternating pave and MOP, but don’t you worry that would have the same effect on you of not being enough pop? They would be stunning, but subtle, more so than the guilloche that you already know is not quite it for you. I think it makes the most sense to try on the GMOP alternating 20 motif, and then you can decide if slightly more contrast would do the trick (onyx), or if you are happy with the GMOP. The nice thing about GMOP is that you can easily take a photo at a certain angle or lighting so it looks like onyx, at least for some of the motifs, so I think you could get a good idea both options.