I have never personally used an Odin, so I can't really comment on their abilities. I can say that there is noone locally to me or with 2000 miles that carries them that I can find. I see no authorized dealers or stores that stock them in the Eastern US or Canada.
As for Pocket Wizard and cables, mine cost me $4.99 so not really a big deal
Availability is a large point for me. I may do a lot of buying online, but I also buy brands that I can also get locally or same day if I need a replacement.
Now if Odin starts getting dealerships in the US or Canada, then maybe I will consider them. So far Pocket Wizards have served me well. They are plentiful, I get them cheaper than I can buy Odins, and if I am traveling and have an issue, loss, etc., I can easily purchase a replacement or borrow one.
The only issue that some are getting with the 580 EX IIs is do to Canon and their frequencies, not the Pocket Wizards. I have had no issues with either of my 580s or 430s and working with them and my Photogenics.
The other thing to note about not needing shielding with Odin's, that is because the frequencies that are used. In fact, while you may not have run into problems do to the frequency spread, since the US uses different ranges for other devices, it can be likely that the Odins may suffer from interference from other devices.
Pocket Wizard will have specific frequency ranges based upon location for this exact reason, and from what I have seen, Odin is only a one size fits all. This also may be a reason, why after 4 years, they seem to only be available in Europe, and not carried by North American or Canadian markets.