What is the best way to save a games state Property list or Text File?

In "iPhone Application Programming Guide" it says

File Access Guidelines
When creating files or writing out file data, keep the following guidelines in mind:

Minimize the amount of data you write to the disk. File operations are relatively slow and involve writing to the Flash disk, which has a limited lifespan. Some specific tips to help you minimize file-related operations include:
Write only the portions of the file that changed, but aggregate changes when you can. Avoid writing out the entire file just to change a few bytes.
When defining your file format, group frequently modified content together so as to minimize the overall number of blocks that need to be written to disk each time.
If your data consists of structured content that is randomly accessed, store it in a SQLite database. This is especially important if the amount of data you are manipulating could grow to be more than a few megabytes in size.
Avoid writing cache files to disk. The only exception to this rule is when your application quits and you need to write state information that can be used to put your application back into the same state when it is next launched.

The data I am looking to save is Game Struct (Object Position,Speed,Size) all 2 vectors

So what would be my best choice?