Being the direct source of force on the string, pick shape and material have a significant impact on the tone produced - much like playing with your fingertips or fingernails has. There is also ease of playing to consider. So I went and tried out a lot of different picks from a lot of makers small and large.
I found only four objective criteria of quality to judge picks since tone is subjective, so they relate to ease of playing. These are volume, grip, durability, and "glide", that is, how much resistance do you feel when the pick moves from one string to the next.
The tone they produce is much louder than most standard nylon picks and a bit louder than the average boutique pick. I only got them two weeks ago, so I can't personally comment on durability, but a glance around the web shows people also buy them for this reason.
These picks are the grippiest I own. They grip better than picks dressed in rubber. I have a 6mm monstrosity and these still feel more stable. It's amazing.
I own one pick made with a glass fiber and polymer composite that glides better than these, but they are better than most of the others I have and as good as the rest.
Timbre-wise they have pronounced upper mids, less treble than nylon picks, but more high end than some other materials. They sound very "full" to my ears. A good tone to have at your disposal, especially considering how great they feel to use.
At this price, everyone should try some variety of a Flow pick.