Hmmm?
Wigma,
I would never discourage you from buying Picasso fins because I love my BTs. However, I chose Picasso because I have wide feet, not narrow. Advice I received on this forum was that the Picasso footpockets are good for wide feet, and I found that advice to be true. I have dived with the same size fin in both Omer Riffe and Picasso BT, and find the Omer footpocket to be a bit narrower in the toe and higher in the back of the heel.
I have heard that the Sporasub footpockets are even narrower, but have not tried them . . . others on the forum are more knowledgable about other fins.
One thing you might try is to speak with Roger Yazbeck at Picasso America and either Matt at Pirate Scuba or Mark Labocetta at Omer and ask them to help you with sizing (I would recommend a neoprene sock with either fin). Tell them you need to try on the various fins and want to send back their fin if it is not the best fit. You'll have to pay the return postage, but it would be less expensive than driving to a dive center, which would likely carry only one brand anyway. You can then try them on at home side by side. You won't be able to get the water with them, but you'll be able to tell how the footpocket feels. I did this, chose the Picasso, and sold the Omers to my brother, whose foot is a bit narrower. We're both very happy and each think our fins are the better.