The Irishman had a stint on the US X Factor earlier this year for auditions while Simon Cowell was ill.
He said that he finds that the UK original still has "the edge", as it continues to find genuine recording stars.
"I did two days on the American show because Simon was sick. I was sat with Britney Spears, Demi Lovato and LA Reid," he is quoted as saying in The Sun.
"I'd work on any of the X Factor shows around the world. I love it.
"But I do think the UK X Factor is different, I think it's got the edge on everything because we always get great personalities.
"The people that show up are incredible. The shows deliver pop stars like Olly Murs, One Direction, Alexandra Burke, Leona Lewis... it's not necessarily the people who win the shows that are successful.
"I mean, look at Jedward. They didn't win but they're still working all the time. Kids love them."
Walsh added that he still misses Simon Cowell on the judging panel of the UK show.
He said: "I miss Simon. He's honest - he's always looking for people who will sell records."
Simon Cowell has been confirmed to make some form of an appearance during this year's UK X Factor series.