I did not have a good experience, but it is not the store's fault. I tried to order this item many times over multiple days but my card was declined every time. Eventually I found out that my card was put on hold for 'suspicious activity' because I had been ordering overseas. When I cleared that up they shipped the 1st monofin i tried to order, a size 12. But all my later orders were the largest size because I have to wear thick socks (I live in Alaska). They did not fit with anything but bare feet. The shipping was $60 and 30 days. So I could not send them back. I have done extensive modifications to get them to fit but even after all that I cannot swim for more than a few minutes before I get severe foot cramps. The final thing I can do is add arch support but then it will make the foot pocket too small again. I have been quite depressed about it as I had important plans involving the monofin. So far I have only been able to use it in the pool barefoot, even thin socks cause cramps.
All of this aside, monofins are not much more efficient than freediving fins, it has almost no turning ability so it is hard to explore. You have to equip and remove them while floating in the water unless you want to drag yourself in and out like Ariel- tho its fun its not practical and damages your wetsuit. I dont see what the big deal is about monofins.