I'm here right now in Truk Lagoon, passing Thorfinn everyday on my way to the wreck divesites. IMO/IME, it's less expensive to stay with a land based dive op/hotel like the Truk Stop Hotel & Truk Lagoon Dive Center, than to be onboard the Thorfinn which is basically a floating hotel with servicing dive tender skiffs.
If you want a true liveaboard that travels to and stays on station over each divesite, and can afford the amenities --the Truk Odyssey is the way to go.
for the average diver, teh difference between a live aboard (odyssey or throfinn) or land based is no big deal.. but those that want to go beyond the norm the Thorfinn offers the best options..
On the odyssey, unless you are on a tech trip, the deep diving is very limited, on the thorfinn he breaks you up into smaller groups and you get to do what you want to do not what the rest of the divers do.. For those trained, the deepr wrecks offer some of the best dives in truk, which I would be upset if I couldn;t do..
With the throfinn I get to do at least 1 deep dive a day (160+) some days two and at least one mid depth dive before I am dived out.. some of my favorite wrecks are hardly ever visited by the odyssey..
The shore based ops will do these deeper wrecks, but usually 2 dives a day is the max you can get due to the additional travel time..
The thorfinn doesnt move much (typically only 2 or 3 times a week) but he does position the ship to best cover a group of wrecks and keep the travel time to a minimum..
The rooms on the thorfin are big (especially the lowest deck), so there is no being cramped.. The comeraderie aboard the live aboards is definately better than the shore based ops (I have stayed at both blue lagoon and truk stop).. SO if your not going with a group the live aboard is a better option..
My favorite wrecks (no particular order) are the (please forgive the spelling I cant look them up right now)
Shotan Maru
Aikoku Mari
Amagisan Maru
San fransisco Maro
Fujisan Maru
Hoki maru
nippo maru
I-689
Oite (so far only dove it once)
The above wrecks I have been able to do on every trip I have made using the thorfinn and sometimes multiple dives..