The common issues that seem to plague the gen2 (I have gen1 never had an issue at all) are FTF/FTE.

Many are buying the VQ or Tacticool22 extractors (never had an issue with my factory one but do have VQ installed - although they seem to be experiencing some QC issues recently).

Before you buy a replacement first check the main fixes for these problems, all of which are available searching this forum or youtube.

1 - Load the mags correctly.
2 - Don't hold the rifle by the mag or rest it off the mag.
3 - Do NOT overlube.
4 - Check correct position of ejector and fix if necessary.
5 - Remember that any work done ie handguard removal or FH removal....the barrel must be clamped not the upper.

Wouldn't hurt to get a barrel nut tool, which allows you to make sure the barrel nut is tight.

I hope that you have a great first outing with your new 15-22. They are fantastic rifles.