Good review!
The product probably isn't for me, but I liked how you tackled and presented it.
I just don't understand how people use such light mice. I prefer heavy mice for stable tracking.
Back when I had a Logitech G5 followed by a G500 I used to run with the weight cartridges maxed out. I did the same for the brief period I had that ugly G502 Proteus Core thing.
Now I use the relaunched MX518. At 99g it was WAY too light for me, but it didn't have a weight cartridge, so I crackled the case and added 3oz of tungsten putty (the kind you use to tune the weight of pinewood derby cars) inside the mouse. This resulted in a 185g mouse which is perfect for me.
I think it comes down to how you use the mouse. I've noticed a lot of kids these days ride their hand on the mouse like it is some sort of car, and move their entire arms to move the mouse, using HUGE mouse pads and very low sensitivity.
Not only is this ergonomically awful (expect repetitive strain injuries by age 30) but it also doesn't feel very effective to me.
I still use my original RatPad. That's all the tracking surface I need. The base of the palm of my hand stays fixed, firmly planted on the desk. The mouse gets moved by twisting my wrist. All the way to the left to all the way to the right represents 360 degrees of motion (so I can turn around 180 degrees by moving either left or right)
The arm never moves at all.
Here is an illustration I made a couple of years ago:
You can't really tell, but there is no weight sitting on top of the mouse at all. The palm of my hand is barely touching it. The entire weight of the hand is resting on the wrist. The fingers kind of drag on either side of the mouse and drag it with them.
The extra weight provides stability, otherwise the whole mouse moves when you - for instance - try to press a mouse button.