First Android/First Smartphone

So next month I'll be getting my first smartphone. I currently own an iPod Touch (64GB 3rd Gen) which I use as my daily driver pretty much. I use it for everything (currently writing this post on it). Anyway I'm stuck between the HTC One and Galaxy S4 to be my first android & smartphone. I love the HTC One build quality and overall look. I've played around with Sense 5 on a friends One and it seemed pretty fast & fluid. My concerns about the One are the camera, lack of SD slot & I've heard that the battery life is a drawback. The Galaxy S4 is appealing to me because it has expandable storage, the 13MP camera & I've heard the battery life is pretty amazing. My concerns about the GS4 are it's build quality, I think it looks kinda cheap, I'm not overly impressed by its Amoled screen & DAT TOUCHWIZ. Every YouTube review of this phone I've seen Touchwiz looks to be slow & jittery, which I think is a joke considering it has a quad ore chip (If I but it'll be the international 8 core chip). But anyway I'm not sure which one to buy so if anyone could state any more Pros/Cons to either phone and help me decided it'd be much appreciated. All feedback welcome!