Definitely don't know if Torvista's is any better.
The functionality of Apsona is based on the javascript that is downloaded from their server every time you start the Apsona page.
My code is the supporting php that you need on your server, it has only been modified so it can continue to work with php7 and current Zen Cart.

unfortunately the code that made it work was never accessible
Not true. Since the browser downloads it, it can be saved and unminified.
With a few modifications here and there it CAN work entirely with all code as local files, but I decided that it was flogging a dead horse and it was time to move on.

DBIO and EP are based on the same concept of using a csv to import data.
EP has a long and checkered history of development and "developers", but now is well-supported I believe. I don't use it.
DBIO is a relatively recent plugin, written by a top developer here from the ground up using modern methods. I use this.