It really doesn't matter what benefits there are. It's free. Which is always a benefit.
But depending on what oil/s you've run in the past the syn may clean the engine out,, sludge and whatnot ,,, but the zetec doesn't sludge bad at all (if any) from what I've seen. So you should be just fine.
And if you're curious about why I say low is better than over (because I'm anxious to explain, just in that kind of mood)
It all has to do with the PCV system.
The air volume the pistons displace in the combustion chambers (~1998cc's) is about equal the the volume they displace in the oil pan. The pan is actually a bit bigger. This is done so pressure doesn't build in the bottom end, which would reduce TQ because the piston has to move through pressure, more resistance.
Too much oil can raise the pressure through the PCV and coat the intake with more oil than normal.
It's one of those things most don't know or think about. So it's just kinda neat to know.