I bought that pick out of curiosity for playing bass guitar.
It really gives a warm, mellow sound, very similar to finger plucking. That was quite surprising actually! It sometimes sounds sort of muffled and imprecise. Attacks aren't as snappy as with finger pads either. Also, being thick, it may take some practice for precision playing.
Although that stuff sheds into tiny bits, I hope it will retains its shape and performance - been only a few days I've been playing around with it.