Ah yeah. The W213 Comand system has welcomed you to its realm of disappointment.
My 2017 E220d Premium Plus has a widescreen display and adaptive cruise control. I agree with you that the car's potential is squandered by the mediocre Comand interface. I agree with everything you've said thus far, and because you specifically requested for feedback on what you could be missing, I'll add a few things you might encounter in the near future:
It might take a while and be unclear when giving directions: The navigation system will give you a heads-up when it's time to make a turn, but it's not uncommon to have already done so by the time the voice instructs you to do so. When approaching a roundabout, it may direct you to take the fifth exit (which is right), but after you're already on the roundabout, it may direct you to take the second or third exit instead. For some reason, it's fallen out of sync with its original intent, which is for you to choose the fifth option.
Do you feel like you're not making many 'right' or 'left' turns? They lean "slight right" or "slight left" in the majority. After a time, it starts to grate on my nerves.
Third, almost a year after they were included, several roads and roundabouts are still absent from the most up-to-date maps. Have seen this in France and the UK.
I recently attempted to locate a certain parking lot in Guidlford that has existed for at least 5 years, but I was unable due to the lack of POIs and the poor quality of the search results. I had to look it up on Google Maps and then type it into Comand by hand since it wasn't there. Like you, I've tried to look for a certain POI by name, only to be forced to manually zoom in on the map and discover it (and sure, it was named the same thing as I had typed in).
5. The map's speed restrictions are often incorrect. This may not seem like a big deal, but there is a little section of the M25 near Dartford where the map indicates that the speed limit is 40 miles per hour. If you're driving in semi-autonomous mode and reach this section, the car will abruptly slow down. Although it hasn't resulted in a collision just yet, things might quickly escalate if you were stuck in heavy traffic with an impatient driver right up your rear end, as often occurs on the M25.
I miss the little window that showed me how much time was left before my next turn, but that's just a nitpick.
7. It has poor street knowledge; for example, it may warn you to "prepare to turn right" when the road really only curves to the right. At the fork in the road, it may advise you to go straight on the majority of the time, but on other occasions, it may instruct you to travel in the other direction.
Voice instructions are interesting number eight. Little Bently is an Essex village. 'Lt Bently' appears on the road signage. It is pronounced "Leftenant Bently" by my GPS. Love the way the road sign reads "Newport (M4)" yet directs you in the direction of "Newport, open brackets M4 close brackets"?
You probably figured by now that the W213 is my biggest pet peeve. It's a real pity since, as you say, otherwise, it's a fantastic vehicle. That is, unless you include the row of controls for the atmosphere, which all seem to be identical and need you to take your eyes from the road in order to determine which one you really want to use.
Before this, I drove a W204 estate equipped with a Becker sat nav (not Comand), and it had many of the same shortcomings (albeit I was able to install speed cameras to that system). This (NTG5.5) is likewise powered by Becker and is a relic of the past when installed in a cutting-edge vehicle. It baffles me how a manufacturer of such groundbreaking F1 vehicles can rationalize such behavior. Before committing to a final design, they should do some rigorous usability testing.
I did take the initiative to contact MB's CEO with my thoughts, but he hasn't yet responded to my letter. Is there anybody from MB that checks the forums?
P.S. - Mercedes, I need to go out to the vehicle again. Again, I see that my windows are open. If the window fairy performs her job as it normally does, she will have shut the windows before I arrive.