Purchased Canon 35 mm 1.4L I - Very soft... did I buy a bad copy?

I purchased a Canon 35mm 1.4L off ebay for about $700. Overall, I really do enjoy the lens, but I've found that it's quite soft even when stopped up to 1.8 and sometimes even 2.0. Is it just the lens? Should I have gotten the second version?I'm using it on a Canon 6D. via /r/photography http://ift.tt/2xBkgBw