Originally Posted by MSD

The ones you push air out of are good, the vacuum ones seemed great at first, but once all the tablecloths and out-of-season clothes were packed and sat on the closet shelf for a few months, they started leaking air in slowly, allowing everything to return to its uncompressed size and forming an impossible-to-remove block of bags wedged between the shelf and the ceiling. I had to throw the upright vacuum over one shoulder and use the hose with the other to suck the air out of one of the bags to get the stack to budge.