I have lots of pics and have been trying them for years. My take is that it depends on what type player you are, what guitars you're playing, your STYLE of playing and then you start making all the fine points. Where you pick on the strings matters an lot, but can be changed to suit a type of pick. Softer pics can feel better, thick rounded pics are faster. If you're a fast picker at all, something like the Vpicks will really let you fly, but at the expense of the "clicky" sound they make that I eventually decided wasn't worth the blazing speed. Tortex pics are more "neutral" sounding in general. Plastic pics "sound" plastic to me (usually). Etc...
My all around "go to" is a green jazz tortex. I like the John Petrucci pick. When I was my best as a player, I used the very small Odessa and Clayton nylon pics. I HATE anything bigger than jazz size. Too clunky for me when I'm jumping around strings. So I never ever use a full sized pick, even though I have some and may strum my Taylors with them in a pinch. Lots more to say. Deep subject. Don't want to ramble. I did a little demo on the sound of some picks one time, while speed picking, but I lost it in a computer crash.
Oh, my absolute #1 for acoustic any time I'm not going to be picking fast, Red Tortex jazz size, pointed tip 50. The notes just BOUNCE off my Taylors with that pick, It literally makes your acoustic guitar sound better, but no DiMeola stuff with it. Too soft. But for even medium speed picking or strumming HANDS DOWN THE pick to have for acoustics. IMHO, consult your physician for .... (I actually demonstrated that in the pick tone demo I did and every single person who listened agreed with the tone being better with it.
