Hey Buddha,
I know what DR Gear will advice as he has the Olympus Mons himself

I have the Millet myself.
Main difference is that Olympus mons have a bit narrower fit; they are a bit more flexible, therefore easier to fronpouint etc with. Millet is supposed to be e bit warmer (-50C compared to -40C or so...)
Anyway, both boots are really only needed if you climb above 7000m or in Alaska, so only get them if you need them as they are both big and clumsy

Do not buy them online; these boots are not made in large numbers so even 2 pairs of the same type and size can differ andf make the difference between (no) blisters or (no) frozen toes. If needed, go to anothe country where you can try them on, walk around for at least half an hour, before choosing type and size.
I know Ron will be happy to sell either of them in Bever Tilburg or The Hague

Just my 2 cents...
Ps: Millet were very warm, the goretex tears easily, and even though they are big, the are relatively light & I had no problem using them on crappy rocks in either Pakistan or Everest this year...