I've never owned a Glock that didn't eject brass erratically. Mind you - they all have been mostly reliable pistols otherwise.
I've never understood why Glock can't develop a pistol that ejects consistently. I've always assumed it had something to do with the strange angled geometry of the extractor arm.
I own and have shot Colts, Walthers, Rugers, Kahrs, Brownings, and others that toss rounds very consistently off to the right. My P99 (which ejects cartridges quite violently) will literally place them all into a neat 1 foot diameter pile about 6' off my right shoulder.