I know its been a long time since this post was started, but here goes anyway.
We dove the Thorfinn 8 years ago, mainly for budgetary reasons. We've heard so much about the Odyssey, but at that time in our lives, we couldn't afford the extra $$, so went with Capt. Higgs and company. A land based option wasn't an option for us - we've read so much about the living conditions on land , the longer boat dives and fewer dives available over a week, that a liveaboard is the only option.
When we went, the Thorfinn divided our group into 3 levels - beginners, intermediates and advanced. The beginners either had relatively fewer dives, minimum 40-50, or weren't experienced at wreck penetration. The intermediates had considerably more dives, some or alot of wreck penetration, while the advanced was for the hard core/ tech divers. We stayed in the intermediate group.
So depending on which group you're assigned to, you get different wrecks to dive. The Fujikawa and Shinkoku were relatively easy dives, and we did a night dive on each, with some limited penetration. Later in the week we had the option of the San Francisco Maru, which at 150 - 180 ft., was heading into advanced territory for us.We opted out.
The service was good, the food, while plentiful, has that cafeteria style food - kind of bland but ok. The guides had varying degrees of English fluency, so depending on who you dove with, your briefing was short or long.But they were experts at pointing out artifacts while on the wrecks, things we probably couldn't find on our own.
One nice feature of this type of diving is that there are never more than 6 divers on a wreck at one time. For photographers, this is great because the chance of having photos occluded by silt is much lower. But on the Odyssey, th is MIGHT be a problem, since the entire boat anchors over a wreck and has the potential to let everyone on the wreck at the same time. Maybe a minor feature, but we liked the fact that sometimes we (my husband and I) were the only divers on a wreck (including the guide).
But keep in mind, this was 8 years ago, so I don't know how much has changed since then.