I have not found any post that gave the right answer so I hope to add to the confusion.
I don't think there is anything wrong with either MSM or MFM map.
Estimated time of arrival is calculated from the recorded moving average speed. If you have been travelling at a constant high speed and then do the routing, you will get a shorter ETA. If you have been crawling through city traffic prior to the routing, then you get a longer ETA.
The trick is to reset the trip data then you can make a sensible comparison. If you reset, the GPS will use the pre-programmed average speed for the vehicle you have chosen. If you choose car, it will be around 70kph. If you choose pedestrian, your ETA will be several days later.
Just reset trip data then check again and see.