I generally recommend a normal (non-duck) stance to beginners as it tends to make it easier to link turns and generally (I say generally because everybody is different) it puts less strain on your back knee.

But, from your post I gather that you've had some practice and are comfortable riding down the mountain. My recommendation would be to play around with the angles a bit: start out with something like a +13 (front) -3 (rear) for a slight duck stance and see how that works. Afterwards, you can make the angles more extreme. Keep fiddling with it until you are comfortable.

Duck stance makes it easier to ride switch which is an advantage for freestyle riding - so it could be advantageous to play around with the angles. Either way it doesn't take much effort to adjust your bindings, so you can try various stances until you find what works for you!

I second the recommendation of testing out duck stance gradually to avoid knee strain. Keep the back foot angle low at first (maybe even start out at 0 degrees). Then gradually increase the angle until it is comfortable. In my opinion, it is not necessary to have the same angles (in opposite directions) in both the front foot and the back foot; although it does help for symmetry if you ride switch a lot (and its even better if you have a non-directional board).

+15 in the front -15 in the back. Works great for me!

If you are thinking about trying park, then definitely consider giving duck a shot. Also widening your stance will give you greater stability when landing.