I saw a couple of previous discussions on this but some time ago. I have two warres with the Happykeeper floor, seems ok so far as very clean. I did have to modify it though
https://photos.app.goo.gl/Z4KDgK9d8YoNg8HU9 Basically the tubes let in too much light, ignore the main photos, ones at the end show a view of the inside
https://photos.app.goo.gl/D4K2h2TgcDMvQiGZA For my hive 30x30cm interior 8 frame hive the 3mm wide gaps between the tubes means the equivalent of an open floor area of about 80sq/cm (9x9xm) or 12sq". Basically 12% of the floor is actually open.
I will be leaving them on in winter as they recommend. Windy and cold but not severe here in central france.
Just something for people to think about.
Happykeeper info here, stores are selling them now
http://www.happykeeper.fr/home.html not convinced by the cure for varroa claim but it helps.
They have a new idea of just a sheet that has the same curve and slots setup to replace screen in a bottom board.
http://www.happykeeper.fr/similitubes-en.html seems to have some limitations re fitting and does not have the lower curve but cheap and quick fix for a manky floor.
I would guess the round tubes disrupt the air so it doesen't blow upwards into the hive. The entrance is 8mm high which suits me here as limits access for hornets and easily just narrowed.
Dave cushman had a version ages ago
http://www.dave-cushman.net/bee/cushmanfloor.html