Quins are unstoppable when in full flow according to Wasps director of rugby Dai Young, but it has been suggested the 2012 champions lack the variety of game to mount a consistent title challenge.
When Newcastle boss Dean Richards was asked last week which teams are chasing a place in May's Premiership final, he overlooked the club he once coached, picking out only Leicester, Saracens and Northampton.
Quins open their campaign against Wasps at the annual London double-header at Twickenham, and O'Shea is convinced their high-tempo game will prove to be successful once again.
"There's been a lot of talk that Quins have been worked out, which is rubbish," the club's director of rugby said.
"Everyone knows the way we play and we ain't changing it! We'll bring that to the party this season, but with an added mental edge.
"We have a certain way we want to play, it's our style and identity. All our players buy into it and we develop our players on that basis.
"It doesn't mean it's the right way, it's just the way that suits us and the type of player we have.
"We've won three trophies in three seasons, which doesn't happen by accident. We know that if we can bring our game to the party, we'll be successful."
Chris Robshaw-led Quins were overpowered 33-16 by Leicester in last season's play-offs, and O'Shea reveals the experience has shaped their preparations over the summer.
"There was a mental challenge that we didn't rise to in that match and that was trying to get the momentum back," he said.
"The question is were we as good as we could have been, and the answer is no. So we've been focusing a lot on our mindset.
"We've been looking at those big momentum shifts and seeing what can be done to make sure they go our way in the future.
"The game is simple, when you win the breakdown and the collisions, you win the game."
Opening the London double-header is London Irish's clash with Saracens, who start summer signing Billy Vunipola at blindside flanker.
One of the teams capable of breaking up the usual title-chasing quartet of Quins, Leicester, Saracens and Northampton are Gloucester, who host Sale in their first fixture.
Northampton give debuts to British and Irish Lions duo Alex Corbisiero and George North against Exeter, with scrum-half Kahn Fotuali'i included on the bench.