For making hash, the dry ice method has many advantages over the cold water/ice method, but you'll never yield as much product as you do with the multi-screened wet method.
If you are more about the instant gratification and simplicity (and easier clean-up) than getting every last drop of goodness, dry ice is the way to go.
With regards to producing kief, it's like magic watching the ensuing blizzard of trichomes falling onto your clean/smooth surface area..
Tips:
You want to get your dry ice in cubes or pellets if possible, otherwise you're going to want to put on some eyewear and gloves and grab a hammer, Break it up into smallish shards..the more shards, the more surface area to make contact with your plant material.
Shake gently and just every few seconds...the objective is not to pulverize the plant material, but to cause your plant material to make direct contact with the dry ice so as to freeze the trichs..they will fall off on their own if frozen and gently agitated. If you shake your bag too hard, you break up the plant material into dust, which CAN fall through the mesh if you beat it up too much...reducing the purity of your end product.
Hair and lint are a nightmare to remove from your kief...clean the room as well as possible of all hair and dust..use an air purifier or your inline carbon filter in the room for an hour prior to the process, then turn off all fans and seal anything that causes a breeze in the room.
Use a large mirror or other clean surface to shake your bag over. Use a couple of layers of parchment paper around the edges of your clean surface to catch the kief that tries to get away. You can shake it back over the clean surface when finished scraping up the big pile and see how much you would have missed...it's always surprising to me how much there is.