Button has remained at the Woking-based team for the new season, which starts with Sunday's Australian Grand Prix, while his fellow British former world champion Hamilton has departed for Mercedes.
Hamilton, the 2008 world champion, said at pre-season testing that he felt Mercedes focused more on the drivers and has spoken repeatedly about feeling inhibited at McLaren.
"The freedom you have in this team is phenomenal," Button countered at the Albert Park circuit. "That is not the same for me, I was very surprised to hear that.
"I've heard so many rumours ... about the way this team is and it's so far from the truth," the 33-year-old added.
"Maybe people in the team are too afraid to say it but it's so not like that, it's such an open team, a friendly team, they will do anything to help you if you have any issues in any way.
"Nothing against my previous teams ... but when I came here, I thought it would be like people perceive it to be, but it's nothing like that, it's such a big family ... and they'll do anything to make us feel comfortable so that when we go racing we're fully focused."
One of Hamilton's apparent bugbears was the amount of time he was forced to spend making appearances for sponsors during his six years with McLaren.
Button said that was part and parcel of the reality of driving for a team which was not backed by a major car manufacturer.
"You need big sponsors to survive in the sport for a team like McLaren and you need to understand that," said Button, who has won the Australian Grand Prix for three of the last four years.
"Initially it was a shock for me when I came here after winning the world championship with Brawn, I had done six sponsor events that year.
"Initially, it's like 'wow, really?' but you adapt and you learn to understand that this is part of this job and you need that to succeed.
"It's not about just doing the work with the sponsor, you have to do a great job with a sponsor because you want to work with the sponsor for a long time."
Button said the amount of work the drivers did with sponsors did not detract from the excellent atmosphere in the team.
"I understand from that point of view that it's very busy, your time is restricted, because you are flying around doing sponsor events," he said.
"But in terms of what you can do as a driver, in terms of what you can do as a driver to develop the car, it's amazing.
"I feel that you have so much freedom and so much help, if you need it. Whatever your issues are you get help here."
Hamilton for his part reiterated on Thursday his delight at having left McLaren for Mercedes, saying he had had more time to spend at home with his family.
"It's not that much different (but) it's put me in a better place," said the 28-year-old, who won four races last year for McLaren.
"I'm settling into the team, It's still a Formula One team so the aim is to win. We've made some big steps forwards but there is still a lot of work to do."