The Retay G19C or G17 models are moch more faithful replicas of the real glock. Their internal mechanism is partly worse, partly better than the Zoraki 917.
The barrel is steel like on a Rohm RG96, but there is no steel in the hammer. The Retay is single action only, but there is a working trigger safety, the Z917 is double action, but no safe way to carry chambered.
The Retay is little bit less expensive here. with cca 10%.
No clear winner:-) None of them are perfect at all.