Thank you for your post.
There are several factors to consider. If you have a lot of non-container fields, then FileMaker needs to access them quickly. When you have a lot of container field entries, FileMaker needs to skip around the file to get the information. In concept, and depending on file size, the less container information in the file, the quicker FileMaker will present the data. Keeping the container field information stored as a reference MAY help speed on large files.
On the other hand, if most of your data contains images, the loading of images is handled immediately by FileMaker rather than reading the path, finding the file and displaying it. A lot is also dependent on the size of the container files. If they are large, you may not notice much time difference.
In other words, you'll have to do some testing to see which works best for you.
Let me know if you need clarification for any of the above concepts.