I like that they are machine wash, I like that they are comfy, cut and cozy, but the main purpose is for me to be able to get out of bed when my son cries in the middle of the night and not have to look for flip flops or some other proper house shoe - this doesn't do that - so it's more of a 'sock' than it is a 'slipper' and in my mind, does not qualify as a 'slipper sock'.  I got a couple of pairs of this older version and a couple of pairs in the newer, non-slip version, and the newer ones are PERFECT!