Super idea, super connector, minimal improvements necessary

I was looking for a distributor that saves space and looks stylish - it should on my Writes table "are", and I also wanted him to include USB ports, as I from annoying plugging and unplugging (and carry) from the USB Plug Adapter simply had enough. So I wanted to try a combination of plug + USB socket.

I bought this PowerCube plug due to the positive reviews.

Unpacked, and pecked (so it does not slip) and the PowerCube works great. He looks very chic, seated at a desk and has, as it is moored now, 3 places for normal plug and the front 2 USB slots free.
Previously negative I noticed is only:
-) A very high humming / shrill noise when the (USB) infected phone is (almost) fully charged - but I can live with that, even though I'm sitting next to
-) Infected stuff - especially from the USB jacks - are really hard pull out (other review talking about a child safety as a cause); In principle, it's okay, but now and then I'd worry that I'm my USB cable broken because I had to apply as firmly

But otherwise a great thing and it may well be / is likely that I'm going to buy more of it!