The Odyssey line has been around for a couple of years. They are certainly interesting technology, and have been extensively tested in commercial
and military applications.
My concerns are two:
1. very high price
2. questionable service
On the second point, while Odyssey provides a great deal of technical info (see the tech papers available on their website), nowhere in the literature have I been able to find the expected number of cycles by depth
of discharge (DOD).
They do state up front that with an 80% DOD the battery
can deliver "up to 400 cycles" if properly recharged. Well, that's great, but in heavy cruising duty that might be only a year or two. I'd like to see the figures for, e.g., a 50% DOD, and compare them to flooded technologies.
Despite these concerns, the battery looks like it would be very good in marine service
if you're willing to shell out the big bucks to acquire them :-)