I have 2 that eject perfectly, as well as any semi-auto I've ever shot. Both Gen4's, a G17 and a G19.
One has the Apex extractor and spring. Don't forget to order a non-LCI spring loaded bearing from Glockparts.com.
The other has the latest non-dipped Glock extractor from Glockparts.com. Call and ask for it specifically. It also has a White Sound Defense 20% extra power extractor depressor plunger spring and the equivalent of a non-LCI spring loaded bearing.
Both setups work for me, and have for others. In my case the Glock non-dipped extractor is possibly a bit better than the Apex, as it will eject without the magazine in place, which the Apex setup will not. That may be due to the guns: I have not tried switching parts around. And I would rather bet on the Apex over the long haul, as it is machined from solid tool steel, whereas all Glock extractors are MIM parts. The Glock non-dipped extractor is a lot less expensive, though.