I forgot all about testing the USB serial port yesterday, until late in the day.
Today, I spent a little bit of time testing it. I tried it on the Linux laptop first and what I thought was the new port was actually the ghost of the docking station port. More reading on Linux serial ports is in my future.
I moved on to my Windows laptop, plugged in the USB serial port, and it connected up with Putty right off on com4. I first ran Zlink on the Apple //c and was able to communicate back and forth.
Once I was sure that worked, I started ADTPro on both the laptop and the Apple //c. I had to change the configuration of the laptop to com4 and the ADTPro linked right up.
My overall feeling is this is a good product. It definitely works on Windows machines. It will probably work on Linux machines, although with a little more work.

they typically show up as ttyUSBx or ttyACMx
(using a debian based linux)
what I do is pop open a terminal and ls /dev/tty* you will see most of a page of ttySx files, then I plug in the USB adapter, give it a few seconds and do the same listing, it should stick out like a sore thumb
Thank you,
I will definitely give that a try.
I tried this and it showed up as /dev/ttyUSB0 on my Ubuntu laptop.
Thanks again