Try posting your question on the Odyssey board:
I was not impressed with an Odyssey amp I have heard. I think it was the tempest, the stereo version. Rather dark, masking details. Pass Labs gear has a totally different sound, some might call it more accurate, or in a negative sense, more analytical.
Depending on the application of both types of amps, I would go for something that is more controlled rather than dark. Large insensitive speakers are already colored and need control. Mixing dark and insensitive equipment might not be of your liking. At best, if money is an issue, you should consider purchasing the Monos used and if not of your liking, reselling. The Pass that you are considering are rather new and not many should be found second hand.
I would be hesitant in taking much advice at the Odyssey Audio forum. How will a group of owners talk about their own equipment and also having it discussed in their forum. Found many people who are writing in a manufacter's forum rather zealot about their own equipment.
Bemopti123, if you are talking about the basic stereo Odyssey Stratos you have to take into consideration that it is the entry level model and the huge difference in price between it and any Pass amplifier. Even so, it has been well reviewed by experts such as Martin G. Dewulf and J. Peter Moncrieff among others, and I wouldn't say they are dark (I used to own them). The Extreme Monos are a totally different animal and still relatively inexpensive ($2,600 pair) as good amps go.