Hi Niakris,
i'm not a Software Architecture expert but i think that Bridge uses a Cache folder to store image preview thumbnails.
In Bridge "Preferences" there is an option "Keep 100% previews in cache" and a dedicated folder called "Cache" where are stored all the image thumbnails after the first opening.
I did a test. I open my 1000+ folder in Bridge in 16 seconds and the same folder in Stocksubmitter in 13 minutes.
I hope I was helpful
Thanks, Bauman