I went with Bluetooth for the keyboard and mouse. The amazon sourced aftermarket keyboard is thin, Rechargeable and has a thin folding case that holds it on a slight angle while in use if wanted for ergos. The mouse is an old logitech I had laying around. I did test the USB ports with a USB mouse on both of the dex to make sure that the whole unit was working. I find I use the keyboard and mouse while docked without the monitor because of the ease of working wherever I want, not just a monitor friendly place. The 1 thing I wish was possible is if you could launch dex by screen mirroring on the s9 plus as opposed to needing an hdmi hookup. But it's still good with a big screen and sending mail, etc.