I started using a pick in the beginning of my bass playing life (ca. 1973) and used whatever I had at hand. Eventually, I settled on a standard Fender heavy after trying many different types (most of which I still have). It worked pretty well. Then, when I entered Berklee in 1982, I stopped using a pick, thinking they'd laugh me out of there if I used a pick, only to discover shortly before graduating, that one of the big influences on the development of the bass department there, Steve Swallow, was a pick user. I sort of wish I had stuck to my guns and kept on playing with the pick on a EB-2D. Anyway, fast forward a few decades and I started pick playing again, I discovered the Dunlop graphite picks, both the Fender shaped 2mm and the big triangle 1.3mm Big Stubby (I got my first from Mike Gordon and then another from Phil Lesh). Sadly, they were discontinued at about that time. Luckily, Telefunken reissued them, but the 1.3mm pick has been discontinued. Anyway, now I use the Fender heavy or extra-heavy on my Starfire and EB-3 with Pyramid flats and a Telefunken 1.3mm for my Modulus TBX 6s with rounds. I haven't tried a felt pick since the 70s, but I don't have fond memories. Maybe I should try them again.