what do you mean iOS or Google ecosystem? you mean about the clouding experience?It boils down to personal preference.
Do you like to be in the iOS ecosystem or do you prefer Google's ecosystem.
Android is more open and offers advantages because of that, but iOS is so well integrated with other apple services/products there's an advantage to that phone.
Try both and see which works/feels the best for you
what do you mean iOS or Google ecosystem? you mean about the clouding experience?
is 5S gonna be different in design?
Yes you are right, but, one important thing i haven't stated is, im moving from a SonyEricsson K750i to a smartphone, so my experience with smart phones is zero, im not aware of what they are capable of, so in other words i cannot judge what will be of use to me!
As I mentioned research is your friend. Check out the phones and your local carrier store. See how they work, feel in your hand and what services are offered. If you're heavy into the Apple world, iOS may be better. If you don't care or like some of the flexibility of Android then go with that.