Hamilton had one podium finish before the upgrade but has had three, along with three fourth place finishes, since.
Asked how he rated the first half of Mercedes' season, the seven-time world champion said: "I've been incredibly proud of everybody. Everyone has been working insanely hard.
"We've been making big steps. I think the biggest step we took was when we got to Monaco and the car has really progressed a lot since then.
"We have a better understanding of where to position the car. It's been a lot more consistent -- podiums, top-five finishes -- which has been great.
"And, generally, we've been getting solid, great reliability. So, there's lots and lots of good bits."
Red Bull is currently unbeaten, with 12 grand prix wins and three wins in the sprint races in the first half of the year.
The reigning champions have already started to focus on developing the 2024 car.
Hamilton thinks the lead team of that chasing pack will continue to change in the second half of the year, which resumes with the Dutch Grand Prix on Aug. 27.
"I don't know how much developing people will be doing in the second part of the season, but I think there will be movement," Hamilton said.
"I don't know what happened to Aston and how they've taken a step back. But I'm sure McLaren was really strong in the second phase.
"Ferrari were very close so dependent on track, I'm sure there'll be some movement in the positions. I hope that we can be a little better."