"Do you consider him good?"
Translation:Uważacie, że on jest dobry?
Really? Look at one of examples: https://en.wikipedia.org/wiki/Complement_(linguistics)#Predicative.2C_subject_and_object_complements
"She considered Ed quite competent."
I really does sound wrong, and I've been speaking English for most of my life. If you take your example, and replace Ed with him, you may see my point. "She considered him quite competent", it really doesn't sound English in the sentence structure; if I was writing that sentence, I'd add "to be" after him: "She considered him to be quite competent."
This really ought to be a one to one translation from English to Polish, or at least something more on the lines of "Do you consider him to be good?"
The fact that something doesn't sound good for someone doesn't mean that it is incorrect. "Ed" is the same object as "him" and the predicative complement is placed at the end. You can also look at definition 1.3: http://www.oxforddictionaries.com/definition/english/consider