FIA president Max Mosley is the latest foe, advising the McLaren principal that dollars might be more wisely spent on a Ferrari-like test track.
After back-to-back - and dominant - victories in Spain and Monaco, the team chairman said the grandiose 'McLaren Technology Centre' is now delivering.
"There were lots of people who were very critical," Dennis agreed.
"The factory allows the engineers the ability to explore every opportunity to improve the car," Ron said, "and attracts the best people. The results are coming now."
Meanwhile, he played down any comparison between McLaren protégé Kimi Raikkonen and the Finn's championship opponent, Spaniard Fernando Alonso.
"It is difficult to distinguish between them in terms of who has the most ability," Dennis continued, "as they're in different cars."