In Minnesota we are not required to disclose. If I have nothing that could tip the officer off (IWB carry, vault, ammunition, holster(s), magazines, knife, flashlight, etc. in plain sight) I make the decision on a case by case basis. If there is evidence of weapons in plain view, or if they may be seen at some point, I will be up front right away.
I have never had an issue! They ask where, I tell them, they give me an instruction or two, and we move forward. The only time an officer took my gun (he didn't really take it - It was like you asking how I like a certain gun and my opinions on it) was because he had interest in it and wanted to handle it. I unholstered, unloaded and handed it to him. When he gave it back I reloaded and holstered.
I can fully understand the advice about disclosing. I have no interest in it if that is your choice. And, I have no problem with people like MB, MJ or RP advising it. They are not only teaching and writing for a national audience, they are advising the lowest common denominator. If someone listens to or reads their advice and acts stupid any "expert" needs to make sure they have covered their own butts in all jurisdictions. A thirty minute TV program, Podcast or a blog is not long enough to educate on all the possible situations, so they must stay general and to the strictest interpretation of any law.