No place like home for O'Brien
While Scotland spent a week in the Pyrenees at the hands of a hostage negotiator and England decamped to Denver's Rocky Mountains, Ireland stayed at home.
"There's not a lot from the outfield that's been thrown at us," said O'Brien, preparing to captain Ireland for the first time against Scotland on Saturday.
"It's whatever the management and coaches saw fit for the players.
"The last five or six weeks have been pretty intense and a lot of hard wok. We felt we could get that done at home and approach it in the right way.
"I think it's been pretty spot-on so far and the players are happy to get home a day a week and see their families, it's nice to have that."
Schmidt's old friend and sparring partner Vern Cotter has taken a vastly-different pre-World Cup approach from Ireland.
The Scotland players endured a week's survival camp in the Pyrenees led by Eric Blondeau, who worked with France's equivalent of the SAS.
England boss Stuart Lancaster took his squad to Denver to capitalise on the fitness benefits of training in an oxygen-deprived high-altitude setting.
Schmidt took Ireland on another internal tour, with open training sessions up and down the country to allow supporters to get close to their heroes.
Leinster loose-forward O'Brien admitted whatever the backdrop, the hard graft of pre-season never changes.
"I think you know when you go into a pre-season how hard it's going to be," said O'Brien.
"I think you're never looking forward to the fitness sessions, they're always intense. But it's gone well and hopefully we're moving in the right direction."