Depends a lot on the situation. At urban public (ie, tax-supported) schools in the US one would generally want something quite rugged and able to stand up to abuse, and also something securely anchored. Quite often you see simple inverted U shapes of heavy pipe with the bottom ends set in concrete, with multiple copies spaced 1/2 to 3/4 meters apart -- the bikes would be leaned against these and locked.
In locations where vandalism and security are not as big an issue you might see racks similar to "The Claw" rack that you linked (though I've never seen that specific style). A problem with this style, though, is that many bikes will not fit the rack, because the tires are wider or it's a BMX bike with a smallish frame or whatever. And that specific style makes it hard to securely lock the bike -- you need a long chain or cable to reach from the rack to the frame or back wheel.
You definitely should look at the mix of bikes in your situation, and the need (or not) to securely lock them to "inform" your rack decision.