I prefer nylon picks because they have a softer feel on the strings to my ear - less "clicky" - than a standard plastic pick.  My favorites are Snarling Dogs Brain Picks which are very similar to these.  I guess when it comes right down to it these are essentially the same, I just have more of the Brain Picks at this point, so I use them more.  But these Dunlop nylon picks are excellent.  They're almost impossible to drop, they sound and feel just right to me, and they last seemingly forever.  Hard to go wrong with these if you like nylon picks.