Calf Cuffs are different for different people, some people like them some don't.
In my opinion I don't get on with them, I don't feel as safe with them, but then again I don't think I have tried them enough, and after a while I am sure id like them more. They are more comfortable aswell.
If you do them correctly (unlike me) they won't come loose, although if you don't do them correctly its very dangerous, I accedently did this once and landed very badly on my ankle.
all in all I suggest finding a group near you before getting them, to try and see if you like
DC