I've done several projects with it and it's very effective stuff.
I first did the boat's fridge/freezer, then wrapped the hot water
tank innards, tossing the whole original insulation and cover.
Next we built a square bag with a zippered top (sunbrella).
It has about 3" of aerogel all the way around and was made to fit one of these:
Amazon.com : Arctic Ice Tundra Series Reusable Cooler Pack : Sports & Outdoors
We purchased two of them, alternating them to the boat's freezer
which averages around 0 degrees f. Once a day, we switch them out. The bag keeps lots of food
frozen, thus enabling us to carry a lot more frozen food
while on vacation
in out of the way places.
The fridge obviously works harder, but the solar
array keeps our LiFePo4 battery
The hot water stays hot a lot longer than with the original insulation.