I started noticing some consistent front-focus problems while I was on a trip, and over some time I settled on a +7 value.
Checking the AF performance of this lens on my 5D3 using FoCal was completely useless due to focus imprecision.
Using DotTune, I confirmed that it needs a +7.5 at distances < 2.5m while it's spot-on at medium distances. I kept the +7 because the DoF is shallower at close distances, but my pictures at medium distances were somewhat affected and with this sort of gap it's very difficult to compromise.
Anyone else who owns this lens encountered similar problems?
I own this lens and have no issues with it - in fact it is the best focussing lens i have owned , you have a faulty lens and should just send it back and get it checked you will be happy you have done so as the lens is amazing.