Rookie manager Monk was under the microscope at the start of the season with many pundits even suggesting Swansea would struggle by putting their 36-year-old former captain in charge.
But Swansea's 1-1 home draw with Everton on Saturday took them to the 47-point mark achieved by Brendan Rodgers' side in the club's inaugural Premier League three seasons ago.
"I think anyone that watches us regularly will say this is the best team and squad we've had, certainly since I've been here," said central defender Williams, a linchpin of Swansea sides under Rodgers and Monk.
"The quality throughout the squad is good because the gaffer has done a good job in January and the summer to bring in players.
"The all-round quality and the way we work in training, the shape we work on, is better.
"We can play different formations and we've got very intelligent players in the team.
"The main thing is the structure of the staff set-up and the players."
Swansea have spent all season in the top half of the table and have done the double over Manchester United as well as beating Arsenal and Southampton along the way.
But Williams said there was a determination not to let the campaign fizzle out and maintain the club's current eighth position, which would better their best Premier League finish of ninth two seasons ago.
"We're safe so that isn't a worry or a concern and we've got different challenges now," Williams said.
"We don't want to finish with a whimper, like we have done in other seasons, we want to finish strongly and beat our targets.
"Finishing eighth would be a really good season for Swansea."
Jonjo Shelvey rescued a point for Swansea and denied Everton a fourth-straight league victory when he drilled home a 69th-minute spot-kick after Seamus Coleman had handled while on the floor under pressure from Marvin Emnes.
Everton manager Roberto Martinez criticised referee Michael Oliver's decision as he felt Coleman had been bundled over by Emnes but he was far happier with Aaron Lennon's calm finish close to half-time
The England winger on loan from Tottenham netting for the second successive away game after failing to score since December 2013.
"Aaron has been terrific and he has got an incredible quality in his finishing," Martinez said.
"He works so hard and has been a big help in what we do off the ball, but on the ball he has quality in those one v one situations.
"He can get in those really good goal-scoring positions and when he does that he is going to hit the back of the net.
"It was a very similar profile to when he scored at QPR and he had a very good chance against Arsenal as well.
"It's good to see him enjoying his football in this fashion."
Source : PA
Source: PA