This is probably the first time I'll speak ill of winspear's picks if only because the material that the Stealth series is made of is nowhere near as durable as his UHMPWE picks (ie bloodline/purity). Pros: +it's a very smooth and quick playing material +minimal pick noise cons: -durability is terrible compared to Winspear's UHMPWE picks. I managed to wear my stealth shiv down into a very beveled nub after only about a week or two, whereas my UHMPWE shivs are still going strong after more than a few months with almost no wear other than some minor rounding of the pointed tip. -The material (PEEK) covers my hands and guitar in a black dust as it wears down, similar to say the carbon fiber jazz iiis that dunlop makes. Not a huge deal but it's not something that I enjoy having to clean up after playing. Overall I'd say avoid the stealth series if you want a pick that will last you a long time. For my personal tastes I prefer extremely durable materials that warm up my picking sound, which UHMPWE does with ease, while PEEK disintegrates at a rate not much better than some far softer materials like acrylic/nylon,etc . No other material that I've used holds up to abuse quite as well as UHMPWE (besides whatever proprietary thermoplastic blue chip uses).