I suspect that you're talking about what we Brits know as an overhead join. They are very common here in Britain, but pretty rare in the US (I've flown one or two).
The principle is simple enough - you join at 1000ft above circuit height (or other height if called for by local procedures) over the main runway centreline, before descending onto deadside (upwind in American), then turning crosswind at circuit height and fitting in with the normal circuit.
It relies upon a very good lookout, since there is risk of intruding into another aircraft's bit of space, particularly during the deadside descent (if somebody else is joining deadside or going around), or during the turn onto downwind since you won't be as far into wind at that turn as you would be if you were flying a conventional circuit. But most other joins require a similar degree of care and lookout so there's nothing particularly scarey there.
Why would be fly an OHJ?, well...
- To take a good look at an unfamiliar airfield.
- If making a non-radio join, you can see the windsock and signal square and get all of the main information you need for your circuit and landing.
- If for any reason you are uncertain of the reliability of your engine, it's possible from most points in an OHJ to convert to a deadstick onto the runway.
- You don't need to descend until overhead the airfield, which in some places (such as where surrounded by high terrain, or close to other airfields) can be advantageous.
So, I'm inclined to agree with your local flight safety mag and say one should regularly practice overhead joins, as well as keeping current on the main signals - since unless you know those, it's a little pointless.
On the other hand, if there's an American procedure that I've not met called an overhead apporoach, which is distinct from an OHJ, please disregard all after "good afternoon" !
G