I played almost every main Assassin's Creed (i skipped 4 and Rogue, but that's it i think) so i guess you could say i'm a fan of the series, despite having hated with a passion quite a few of them.
I dumped 80+ hours into Origins, and 11 into Odyssey, and i have to say, i personally liked Origins more, so far.
Odyssey has more interesting game design elements (feels closer to a Bioware-style rpg) and the dialogue choices are a genuinely decent way to keep you interested in the story, despite it being the usual tripe Ubisoft writing (like all AC's past 2).
However the setting has just lost a lot of verisimilitude and naturalistic feel (they just went full mythology even with the geography, with giant statues around every corner) this was somewhat true in Origins as well, but it felt more toned down there; plus i guess i like Egypt more than Greece.
And the game just feels less weighty and polished in general, despite being almost a copycat; it's still good fun though, and Origins was the best AC since 2 (being better than it in everything but story, too) so even a step down from it isn't too bad.
In general, i'm very happy with this new formula, because it allows them to explore virtually any historical setting without limits, whereas the past iterations were more tied to the idea of a dense and vertically complex metropolis.
They could do one in pre colonial India, birth of the Persian Empire, Mongol empire, 30 years war, Spanish conquistadores in the Americas, etc etc any number of cool shit, and this gameplay formula would adapt perfectly.
It works on vertical as well as horizontal level design, and allows for really massive and varied maps, with a seamless mix of urban and natural environments.
Origins was a big turning point for the series i think, and it's a shame it got kind of looked over, but at least it seems Odyssey it getting some attention, despite not finding it quite as good, myself.