I went ahead and weighed both crank and electric windows, but my bathroom scale did not have the precision to tell the difference. Each side's assembly weighs 4 lbs.
Here is the conclusion.
Before you start, make sure you remove the foam off the electric wiring, which is the most PIA part of this process. There should be 2 zip-ties, which you will need to cut and remove.
Here is some more information for the removal / install:
Numbers 1-5, 8 all need to be removed, along with two other nuts off of the base (where 8 is). These are all the bolts that hold the mechanical lift onto the car. Make sure you have the window all the way up, then remove the lift mechanism.
6 & 7 will be new mounting locations for the motor / lift assembly.
You will need to remove a copper or aluminum piece from behind the door handle:
This will need to be cut in order to make room for the electrical motor mount:
An aluminum piece will need to be bolted (using existing bolts) to the window base:
This will be your new mounting point for the electrical lift to the window (rather than using the mechanical system's rollers.
You will need to have someone hold the window up, while you first put in the long elevator mechanism (to the right) and then put in your motor / regulator.
The second side took me about 1/3-1/2 of the amount of time it took the first time - GOOD LUCK!! I would rate this about 5 out of 10 in terms of difficulty level, mostly due to the tight space.