It doesn't beep or do AC line detection, BUT it does exactly what you need - it detects studs. I've found the cheap ones either don't work or are inaccurate. This one works well, although I've had a few occasions where it hasn't detected studs accurately. It could be the wall material, if there is ply behind or something.
The design also makes it super quick to mark both sides of a stud rather than slowly sliding it along to find and mark each side. You can even use it to immediately mark where the screw should go instead of having extra marks on the wall.