在iPhone上存储json数据：保存json字符串，因为它是从json创建一个对象并使用NSCoding + NSKeyedArchiver

In my iPhone application I get json data from a remote server, parse it using the Json Framework and present it in a UIview. Also want to be able to give the user the option to store the data on the device so that it can also be viewed offline. I was wondering if storing the json data directly is a better or worse choice than making an object and then saving it using NSCoding + NSKeyedArchiver. I assume that the advantage of storing a json string as it is, is that it takes less space on disc than an archived object while, on the other hand, by storing archived objects you don't have to parse the stored data every time thus using less memory.In my iPhone application I get json data from a