The Croatian boss was appointed to take over from Sam Allardyce at the start of the campaign, and he has guided the side to a very impressive campaign so far.
The Hammers have climbed into sixth place in the Premier League table, and Wilkins feels that the London club have made vast strides.
“I think first and foremost he brought in some very good players,” the former Chelsea assistant manager said.
“They seem a different side. They are solid and workmanlike. They have a great atmosphere amongst the guys.
“They look a really solid outfit, and they will give anyone a game. They’ve been outstanding.”
West Ham have lost just two of their last 18 matches in all competitions, and they are unbeaten in 13 home games.
The Hammers’ strong form has helped them climb the Premier League, and they are now in with a chance of claiming a European spot.
West Ham are only four points behind Manchester City, who occupy the final spot in the Champions League qualification spaces.
Bilic’s men do face a tough test on Wednesday night, however, as Tottenham Hotspur are the next visitors at Upton Park.
Spurs have become the bookies’ favourites to win the Premier League this season, and they will be aiming to strengthen their bid for top spot by beating the Hammers tomorrow.