Its a good product if you are a big studio with permanent premises and are sticking relatively heavy materials on your walls. I gave my second can to a friends permanent studio and his sound treatment as never fallen down since.
At a very good price point, I'd recommend (for at least a "try") to any big and permanent studio
However....for home studios and those in temporary premises (even long-term renters) AVOID THIS PRODUCT.
It is hard to apply to the walls, and once it is applied, it is messy and the foam takes a bit of pressing to get it to stick.
To be fair, its wont fall down accidentally once applied.
But if you want to remove any foam from your walls that were applied with this, you will likely need to cut the foam away, or if you pull it off, expect a lot of foam to stick to the glue on the walls. Removing the glue afterwards is almost impossible, and you will likely lose any security deposit from a rented accommodation.
For the home studio user, or those in a studio that is likely to move within a year or two: AVOID THIS PRODUCT, as it is NOT FOR YOU. There are better, albeit slightly more expensive alternatives out there that are easier to apply, easier to remove and are less hassle than this.
For permanent location stuidos / "big" studios, at this price, I'd definitely recommend a trial of this product.