Mark,
Mystic has too many negatives when compared to Photobucket. Mystic allows only one, small size of picture, it's not nearly as easily navigable and easily modified, you can't upload more than one at a time (PB up to 19 at a time), without upgrading, it doesn't provide one-click pre-filled out code for posting in threads such as here, and you must purchase paper photos at least once per year.