As I swoooooosh majestically through corners like the well seasoned grand tourer that I am in my FWD car.... 
no, lets not start that one again
Keeping momentum seems like a good idea on the basis that if you lose speed then you may have to spend fuel (thats my new phrase, "spend fuel") to get that speed back again. DFCO is good when you have to slow - timing lights for example - or when going on a long downhill section. It also means that you don't brake all the way down so if you have to stop suddenly, people can see that happening.
One of my annoyances at the moment is roundabouts, or rather people who don't seem able to anticipate them, so often I end up having to slow or even stop when it is not needed. So a gap in front is also a good thing.