We use this tool regularly at Shakespeare Solutions and find that it will often help locate studs in modern dry walls where other stud finders fail. In fact we liked it so much that we become the distributor for Australia and New Zealand.
It is simply the best tool for locating studs in a home or apartment built with steel studs but obviously will also locate the nails and screws used to fix plaster to the wall, thereby locating the studs on these walls.
A brilliant tool, we highly recommend having one (or two!) in your tool box when installing our picture hanging systems.