The Planet Waves picks are great. You really can't complain at all. They are fairly thick (1mm) and have a nice feel to them. They have a satin feel to them, which makes them very comfortable for me. Other picks I've tried in the past felt glossy and sticky... not very comfortable at all.
I play with thicker strings most of the time (11-56) and pick really hard. That means they wear down faster than normally. Keeping that in mind they still last for a pretty long time.
Because of their medium size, they are easy to grip.
The only negative I could come up with would be that they look scratched and very dull, but they are picks so who cares really?
Would definitely recommend them!