5s or S5 and other details xD?

Basically I want a new phone donno what to get. I'm contemplating either the galaxy S5 for the iphone 5s or maybe, maybe the galaxy S5 Duos. Now first could you give me advice on the positives in both phones (excluding the duos) do they lag? Are they powerful, or does one have significantly more processing power?
Do they have any significant problems?

Also is the fatal camera error with the galaxy S5 fixed? Does the Duos have the error? Other than they dual sim card how is the duos different from the S5? Any help is much appreciated.

Each phone is works fast and errors have been fixed. The main question what your going to have to answer is do you want android or apple? Also do you want a big screen or small screen? S5 will have a lot more features than the iphone and with an expandable memory slot personally s5 is way better phone overall, although apple products do hold their value more and the iphone will be able to run high resolution games a little better. Just the iphone will limit you and the Galaxy won't. Up to you though.