They don't list it, but a critical feature of their microscope is the stereo or binocular eyepieces, which allow you to see depth. Single-eyepiece lab microscopes do not let you see how high or low the soldering iron tip is from the board!

A TL;DR:

1. Binocular microscope to see depth.

2. 4" or greater working distance, achieved with a Barlow lens, not <1" as on other microscopes.

3. The best and brightest ring light you can afford.

4. Stable mount.

Also, with regards to #3, I found their recommendation of LED ring lights odd:

> At $30/each and requiring us to keep a few in stock in case one blew, we found that although halogen lights made it easier and clearer when examining motherboards, the reliability, flexibility, and low operating cost of LED lights prevailed in the end.

Surely $30 every 3-4 months is a tiny fraction of what their work is worth. I pay that without hesitation, because the light is just better. Also, the 200W heat of the halogen bulb is far away, at the end of a fiber optic cable, while the 40W of LED lights is right under my eyes and near my hands, and I have a gentle fan to move soldering fumes away so only the latter is bothersome.