For AF speed, noise, accuracy, etc, I noticed nothing different between Canon and this one at any time.

For someone who just can’t justify $100/$125 for the Canon 50mm f/1.8 II, the Yongnuo 50mm f/1.8 might be a great option.

http://petapixel.com/2014/12/25/first-review-40-yongnuo-50mm-f1-8-nifty-fifty-clone/

One of the big stories in the world of camera gear this past year has been Chinese manufacturer Yongnuo’s expansion into cheap clones of Canon lenses. While Canon shooters are buzzing about their new budget glass options, Nikon photographers have been wondering if Yongnuo will ever offer clones of their favorite lenses.

We’ve got the scoop that answers that question: Yongnuo will offer cheaper clones of Nikon lenses by the end of 2015.

http://petapixel.com/2014/12/31/yongnuo-will-unveil-cheaper-clones-nikon-lenses-end-2015/

Yongnuo’s clone looks as though it may offer even better value for money for those on a budget, as it performs very similarly to the Canon optic and handles exactly the same.

http://www.ephotozine.com/article/yongnuo-50mm-f-1-8-lens-review--27225

Yongnuo 50mm f1.8 Lens on a RED Cinema Camera