The GST is a bit boxy for me...I prefer the medallion. I like how it hugs the side and I feel it's more versatile in terms of being able to wear it during the daytime and with evening attire. It's also apart of the classic collection so you know it'll be around forever!
Another vote for the GST. Love the amount of room and the style. If you are very petite or don't carry very much then you might want to go for the PST.