Military Arms Channel takes a look at the 5.7x28mm round versus your standard .22 WMR bullet. He shoots them out of their respective pistols. A FNH Five Seven and a Kel-Tec PMR-30. He even uses a SBR PS90 for the test.
The test consists of seeing if over the counter ball ammo can defeat a certain level of body armor. The results are surprising. I would not expect .22WMR to have as much of an effect as this test shows.