Thanks for the link. I watched the video just now. I notice the gal doing the demo and review made quite a few remarks about the score lines being "off" and said she recommended measuring twice, not once like the directions say.
And, indeed, a couple of the envies she made were not terribly accurate. However, I also noticed that she had what I would call a "slap-dash" approach to what she was doing. She was working very fast when rotating the paper and scoring.
I also noticed that she did not seem to get the paper aligned to exactly the right measurement to start with. When you are dealing with 1/8th of an inch, if that measurement starts off wrong, it will be multiplied by the time you complete the other 3 score lines. And, yes, your envelope will not be even.
So, maybe some of the complaints she had could be due to user error?
People doing videos frequently seem to me to be trying to show how fast they can do something, not how carefully and correctly they can do it.
Just my opinion after watching. I haven't used this product.