Overall, I found the article to be written in a pretty level-headed manner.
As to the subject of "informing", we've had several incidents take place here in Missouri that would certainly make a person think twice. There have been several cases of loaded firearms being handled on the side of the road by police officers in a very unsafe manner while they attempted to clear them and (ironically) "make them safe". They, quite simply, didn't know how to operate those particular guns. There have also been instances where officers illegally seized firearms and illegally ran serial numbers, as well as instances where they illegally seized them and made the owner jump through hoops to prove ownership before they returned the property they illegally confiscated. On the positive side, we have a pretty strong RKBA organization here and we're pretty good about acting swiftly and decisively when this kind of stuff happens. The offending departments are no longer illegally running serial numbers or confiscating firearms as a matter of policy, to my knowledge.
My personal policy is to judge each situation on it's own merit. I don't believe it's prudent to arbitrarily inform in every situation. Likewise, there are times when informing the officer could be the prudent thing to do.
In any stop where, in my judgment, I don't believe I will be asked to step out of the vehicle, I don't really see much sense in injecting a firearm into the issue and (perhaps) providing the officer with an opening to feed his ego (if he has one) and "assert his authority" over me, the "lowly" citizen. On the other hand, if I believe the stop is going to involve removal from the vehicle and possibly a pat down, I will likely inform in advance of that action to (hopefully) avoid having some cop point his Glock at me on the side of the road when he "discovers" the gun that, in his view, I was "hiding".
While the vast majority of Police Officer's I know, have met, and have dealt with over the years are good, honest, and professional people, not all of them are. Like any other group of people, there are some losers that, despite the correct legal process for handling a situation, will make it up as they go and follow their own, made-up process for handling a stop. Fighting with one of these clowns on the side of the road, no matter how wrong he/she is, is the wrong thing to do. A little common sense goes a long way when faced with a traffic stop while you are armed.