I don't have personal
experience with it, but as for any kitchen item, I'd recommend trying the old-fashioned way first.
If you have a good blender, nut milks are really easy to do: soak the nuts (or not... I have a good Blendtec and do not always soak first), blend, then pour through a clean kitchen towel into a glass jar. I guess the Almond Cow simplifies the kitchen towel part, but you could use a French Press if you'd prefer.
Chances are the Almond Cow is not as good/reliable a blender and parts will be harder to find when it breaks. I always prefer ONE kitchen device on my countertop that does everything than a lot of single-use items.