If you look at their patent carefully a specially if you have any engineering background or talent, you may decide that you see one or two points where the design is not perfectly adequate.
Which can help if you're stuck in the store without a list. But as technology gets smarter, a term used for when devices are connected to the internet, there are some downsides.
There are of course drawbacks to both states, being single and being in a couple: loneliness in the one; suffocation, anger and frustration in the other.
If you've got a negative feature in your life, like you're not tall or you're fat, you maybe can't do anything about it, so that's not nice to talk about.
Others have combined glass with solar cells that are thinner and smaller but they can have drawbacks like lower power efficiency and less transparency.