I haven’t used one, so have no view on it, but the guy behind it, John @wombatbucketuk , is happy to give the inside scoop.
If you have used one, let us know what you thought. If you haven’t, you are invited to ask the hard questions, like how is it better than a Wooster Pelican etc!!
If you want to buy one, they are available from MyPaintBrush