I run a Brother MFC-9970CDW.  Color machine that uses the TN-315X cartridge.  When I first bought it I could get cheap OEM through Costco and get a free small case of paper free with each cartridge - I should have bought a bunch more back then.

I then tried a couple different brands to see how it would work.  For awhile it seemed to work but then it seemed I was getting a lot of bad cartridges.  I gave up and went back to OEM.  I usually get from B&H Photo but at times get from Costco Business.

My color photos now are always looking good.  If I only did a few graphics and didn't care that color was always right and also may have some streaks, it would be worth the savings. 

But for me I am staying with OEM.