The American, currently on a claycourt winning streak of 17 matches, has won at all four Grand Slam venues, collecting 13 singles titles in total, but just one of those has come at the French Open.
Some therefore have qualms about installing Williams as the favourite for the French Open, which starts on Sunday, but not Wade.
"She's been playing such amazing tennis," Wade told sportinglife.com.
"She's playing just as well as ever and she's certainly fitter than at some times.
"Confidence is high and the only problem when you are winning so easily is you can say 'I'm not used to a challenge' when it comes. She's almost winning too easily.
"When I was in Charleston (in April) she was she doing things not possible.
"She was hitting a winning return, a winning serve, all the time. It's a real purple patch."
Wade, who will be working as a pundit for British Eurosport during the French Open, added: "Serena is such a great front-runner. Her opponents start panicking very early.
"Opponents step out there and then just roll over - she intimidates them that much.
"If anybody could return well and get the serves back in - not just pop them up - they would be able to compete with her but it doesn't happen too often."
Asked about the other title contenders, Wade picks out defending champion Li Na, world number one Victoria Azarenka and the in-form Maria Sharapova.
However, Wade feels Li's confidence has not returned to its high of 12 months ago, has concerns about Azarenka's service action and says that despite wins in Stuttgart and Rome in the past month, Sharapova could have mental scars from her Madrid meeting with Serena, one she lost 6-1 6-3.
"Since she's been working with Thomas Hogstedt, her tactical sense has improved - she hits behind the players a lot - but when Serena played her it was a bit of an annihilation," added the 1977 queen of SW19.
"I would have to go with Serena (as a likely winner)."
Wade is not concerned that Williams is likely to be seeded five and could therefore have to beat Li, Azarenka and Sharapova back-to-back to win the title.
She said: "At the moment all the players will be hoping she's not in their section. I don't think it matters (to Serena)."
Wade, now 66, is also not unduly worried about Williams' withdrawal in Rome last week due to a back problem.
"She was being ultra careful, protecting it," added the Briton.
"She feels she was winning so comfortably and wanted to go to Paris with that feeling - perserving the image of playing perfect tennis.
"If she wasn't feeling 100 per cent she wouldn't want to mess that feeling up."