SWF vs PNG image

Folks,

My flash application loaded png images using MovieLoader.loadClip. Some of those png images are now .svg and so in order for the application to render it, I am first getting them converted to swf. I have tried loading the new swf using loadClip and I see that everything works as before.
I am a beginner as far as flash is concerned and need to gauge if there are any limitations/ pros and cons of replacing the png with swf. From my preliminary search I have found that swf is high quality but slow loading. Our requirements are not exactly real-time and so slow loading isnt much of a concern. Are there other technical cons to be aware of when using swf format for every image that is loaded in the application?

Thanks,