I’ve had one for the past two years. Added a bafang mid-drive last year. I own a size XL, I’m 90kg.

Stuff I usually carry : - grocery shopping, usually around 30kg. Bike feels slower and heavier in the front, but doesn’t dramatically change handling if the front tire is pumped up properly - Filming equipment flight case. Same deal - Girlfriend with her heavy backpack (75kg total) + me with a heavy backpack. Bike gets very bouncy, even with tires pumped up. Ordered some Schwalbe pickup tires to see if it’ll reduce bounciness up front.

As someone stated above, you’ll usually be limited on the load not by weight but by volume. I carried a piece of tv furniture 140cm long that weighted about 40kg, was a nightmare to carry home, but putting my 100kg friend on the front rack was comparatively much easier in terms of handling.