There was a write-up about it in Combat Arms some time ago. Yes, it's designed for PDW and handgun useage, like the FN 5.7. Small caliber, high velocity, with penetrator for use against body armored troops.
The 5.8 rifle round is just now becoming available in the West. It appears to be a slightly different take on the penetration vs. wounding direction taken by the Soviets and the West. There was a tech blurb by David Fortier in a recent Shotgun News issue about the "Sniper" and Machinegun ammunition in this caliber.
The ammo appears to have issues in the field, theory not withstanding. QC is lacking. The weapons themselves were rushed into production for introduction at the Hong Kong turn-over, and they are now playing catch-up on such matters as safety location, reliability, and accuracy. Sounds suspiciously like us in the 1960s with the M16.