I really like these picks as they give you a very positive feeling contact with the strings. The only downside with them is that the pointy end gets rounded off after a while and the 1mm missing off the end affects the feel so you need to start over with a new one. But a pack of 5 lasts a year so the cost is hardly prohibitive.
If you like a bit of ompfff in your plectrum but with the ability to play sensitive lines then these are perfect. Gypsy jazz players will probably love them as well, being 3mm thick. They are totally rigid, giving you full control, and they feel good in your fingers as well.
These are a bit too thick for my taste - I bought soem 1.0mmm, some 2.0mm and these as a mixed bag to try - they have no flex in them, and are a bit clumsy (to me) for bass guitar, but they do have a great "grip" in the fingers.
Its a plectrum! what more do you want to know? I love these "big stubbys" I amso used to them I cant use anything else. You wont go back if you get used to playing with one of these. makes your tone alot warmer too. great for jazz!