Android 4.4 is Google's best defense against fragmenting its audience further. Kitkat can perform a variety of tasks related to search. Apps are more integrated into the system and the next Android will have an impressive HDR+ camera attached to it. Non Android Apps can work on Android 4.4 adding another level of accessibility. The system detects open areas of memory and tells the user if the program can fit the allotted memory. Also, the 512 GM of RAM is perfect since it can be programmed on lower end Android gadgets. The best part is how they've streamlined search for the service. Google Now and Voice recognition are now essential parts of Google's main function.
Now, iOS 7 had its fair share of problems when Apple finally rolled it out. Ranging from massive memory consumption to painfully slow downloads, it wasn't perfect. Looking past these transgressions, iOS 7 is an awesome operating system. Beginning with the new design, the animations are smooth and much more visually pleasing. Other elements include the ability to automatically update apps to the creation of iTunes radio.
So which is better? I'd have to go with Android 4.4. iOS 7 had its time to shine but the new Android OS is very impressive. Personally, I feel that Google needs to do more work on uniting their products to prevent further fracturing but that won't happen. I was most impressed with how Google has linked all their services together. Deeper search answers for apps as well as a more responsive voice scan means the company is doing the best they can to develop the best OS out there.