I used Speedo Optimus fins for years. Always loved them for my 3-4 mile swims. However, the cut at the toes tore CONSTANTLY. Really had to replace them every 4 mos or so. Went with the TYR CrossBlade to see if they could outlast the Optimus and they have. No Tears in 5 months of use. My only concern is that the fin is a bit wider and seems to change the angle of my ankle on my kick. I''ve adjusted, but would prefer the slightly narrower Optimus. The TYR certainly have presented the greatest amount of resistance and improved strength. Also, in general, for all fin users, forget the fin socks and use Aquaphor to keep your feet from blistering if your fins fit well.

This is a great fin. I also use the burner, just depends on the type of work out but these can really get you moving. They really work the legs and are great for IM sets. They may feel a little snug at first but they soften up and fit great.

I wear a Women''s 10.5 in normal shoes. Bought TYR CrossBlade Training Fin in Size 9-11(Red). There were too small; my toes were hanging over at the top.

Had to send it back and order the bigger one.  I wear an 11.5 shoe and the 11 - 13 was too small.  The 13 - 15 fits snug.

Extremely narrow.  I ordered a size larger and still too tight to wear.  My wife''s pair just fit but she has a narrow foot.

I was looking for a training fin that was large enough for my foot (size 14)... these fit the bill! They fit snugly but not too tight.. perfect for workouts in the pool