Yes those snails went fast. They are the most amazing FW snails imo. They went to a good home and all of them made shipping and are alive and well.
There arent too many disadvantages with normal snails. unless they overpopulate the tank and crash it. they can make the water smell bad with their waste if that happens.
Stay away from apple snails, columbian ramshorns, and sulawesi snails for planted bowls. those will eat some plants. and don't keep assassin snails in shrimp bowls, as sometimes they can kill shrimp.
Yes you can buy cheap cherry shrimp in the classified section of our forum here. plenty of invert sellers have them for cheap.