Awesome, fast, fun...after a short learning curve it was amazing.  I consider myself to be a good swimmer, but this thing humbled me.  in the pool it is a fun and tough tool.  In open water it is a whole other animal!  I got the honor of being visited by a dolphin as I played with the monofin in VA beach...it was an awesome experience.  For body surfing it was amazing…just be careful of your knees as the fin is a lot of leverage in a wave during a wipeout    On the negatives:  I have small feet…most of the time I wear a size 8 men’s…yet in these I need a large and it is pretty snug.  Also, putting them on it kinda tricky as can be taking them off.  I you are going to use them in a pool there is one HUGE warning.  These things are sharp.  I mean finning someone is going to draw serious blood.  So not the best plan for lane sharing.

love it!

I am on the bottom end of the sizing range so mine is not too small.  It is appropriately snug so I could see where someone would consider going up a size if they were on the top end of range.  

Takes a little getting used to for a first time monofinner but after a few sessions, you feel like your flying through the water.  My labrador retrievers can't keep in the open water!  Sometimes I get to going so fast, my goggles come off and my ear buds come out (Nu Dolphin - also highly recommended).  

Such a great core workout.  If your ankles are weak like mine (too many sprains in the past playing basketball), then you might want to ease into it with alternating sessions with and without the monofin.