It's basically an MP5 in rifle form. What this has:
Older action type - the delayed blowback dates from WWII. Most AR-15s use direct impingement that has less recoil, but the HK93 will go longer without cleaning before it'll start to affect function.
Wider rifling twist - HK43s have 1:12 twist, whereas AR-15s have up to 1:7. Tighter twists generally make the round more stable at longer ranges until impact.
Weight - The HK93 is heavier than the average AR by a couple pounds.
Magazines - Proprietary, i.e. no STANAG magazines.
That's really nutshelling it. Century basically makes copies though their quality seems to be hit or miss. I would not touch a WASR from them with a ten-foot pole.