I have used space bags in the past and have found that they do their job well. This model has a nice design because it has a relatively small footprint, is stackable, and the plastic part is protected by the canvas exterior, which makes punctures less likely.
A big warning, however: do not overstuff these bags, as they will rip very easily. I was putting a large duvet in one a bit recklessly and the seam busted without a lot of resistance.