I think we should have a better standard to rate stealth in reviews. The purpose of stealth is to HIDE the product from any unwanted eye. By product I mean not only the shit but also its package: mylar bags, vacuum sealed bags, etc.
The stealth must be a visual barrier between the ENTIRE product and any eye, included the customer! This is my proposal to rate stealth:
*0- No visual barrier: the product is just inside in the envelope.
*1- 5: simple visual barrier: there is something else with the product but not a properly decoy.
*6-8: basic stealth: you can check inside the envelope and you won't find the product except if you need to check and again and in certain way 'destroy' the envelope's content to find the product.
*9-10: ninja stealth: this should an EXCEPTION because I have never received something at this level. I think you will need time to figure where is the product and for at least a few seconds your thoughts will include that probably you were scammed.
That's all. I don't understand why a mylar bag in an envelope is considered as a 9/10 stealth. My advice is that you should not trust the stealth section in the vast majority of reviews.
Here's the thing, and it's just one person's opinion man ;-): If someone is looking inside your envelope or box you are 99% fucked. If it's LE they already are suspicious for some reason and are not going to stop if they don't see what they are looking for right away. i.e. if they are looking in the pack, they are going to open the pack and thoroughly search it. 99% of stealth issues are related to the outside of the pack (aside from odor, but that is a given IMO, no odor should escape interior packaging).
I suppose some decoy might be helpful to trick an amateur trying to steal shit, like a bad USPS worker or something, but in my experience that is an extremely rare occurrence.
Of course the more stealth the better, but at a certain point logistics of time and money limit things to what is effective. If you find a vendor that goes above and beyond that's great, but basic vacuum/MBB with a totally normal exterior works fine doesn't it?