I tried those alaska picks, couldn't get on with them and ended up going back to 'nationals.'
The only well known performer i've seen using them (alaskas i mean) is Christina Olson.

In theory they sound great but they don't seem to have caught on.

Strolling Johny's right about them falling off sometimes. It certainly adds a bit of excitment when one falls off into the sound hole during a performance!