I would recommend it. As long as you have the time and the money for the visit, it's worth it. I took my kids in 2019 for one day, as we had 4 days in Paris. (was also there in 2017 solo as part of the runDisney events) Very easy metro/RER ride out and back in one day. As already mentioned, the little differences are what makes it so special. My older kids absolutely loved the differences in the rides! And the castle is just beautiful.
As far as smoking goes, we did not encounter any in the queues (well, maybe once actually), but there were definitely no rules as to otherwise when and where people would be smoking. This was before masks and my kids kept pulling their shirts up over their noses as it drove them crazy. It's all over europe, esp Paris, so not just a DLP thing. Maybe it's gotten better in the last two years? I don't know.
They still have the mask rule, correct? I don't keep up on DLP. But if they do, perhaps that will help and the smokers will actually have to go to the designated smoking areas instead of just lighting up whilst walking, I don't know!