Armitage, Jonny Wilkinson and company will aim to end Toulon's 20-year wait for a major trophy when they tackle Biarritz at the Twickenham Stoop on Friday night.
"Bernard has brought his own distinctive game plan with him," said former London Irish flanker Armitage. "And although Toulon are regarded as big spenders, he also makes sure that everyone keeps their feet on the ground and everyone is equal."
Armitage continued: "He has given players the opportunity to come out of their shells and play their own kind of rugby, while also keeping to his game plan which works pretty well for everyone.
"We are not scared of anyone. On our day we have got the players to win games, so the only important thing to Toulon was that we were there for the final and not who we are playing."
While Toulon remain in French Top 14 title contention, Biarritz can only qualify for next season's Heineken Cup if they win the Amlin trophy, having finished outside the league's leading six positions.
They do, though, have considerable experience of top-flight European competition, finishing as Heineken Cup runners-up in 2006 and 2010.
"It's a game with a double goal for us," Biarritz and France back-row star Imanol Harinordoquy said. "A victory would give us a new title and a ticket for the Heineken Cup next season.
"It would a great reward for our squad, which has suffered this season. It's a huge game with a huge amount at stake, and we are going to work as hard as we can to win it."