According to Fred Miranda over at FM:
"Yes, my R.J. adapter copy shows more CA, especially in the corners. I would stick with Metabones."
"Images from the Sony A7R + Metabones have amazing center resolution, noticeably higher than Canon's with the same lens but the corners do not show the same improvement...I just ordered another Metabones to make sure, but it looks like Roger [Ciccala at Lens' Rentals] was right when he wrote there is no free lunch when adapting our lenses."http://www.fredmiranda.com/forum/topic/1247661/90