I have a very good and professional bass guitar, a Schecter Hellraiser Extreme 5, but my amp, a Crate BT15 is a cheap one, which does not handle my bass appropriately. So I am always in the look for strings that will give me that sound closer to the sound of when I play in a big amp. Pyramid strings are exactly that. They sound new for a long time, they have a very good clarity, they are not floppy and additionally there is a great sound resemblance from string to string, especially from the B and E strings to the others, a hard thing to find. I haven't found out yet anything about their duration, since I am using them for a couple of months yet, but so far they don't seem to have lost their liveliness at all. There is only one thing that I don't particularly like: it takes some time to lose this out-of-the-box brittleness and treble tone, that I can't wait for it to disappear each time I buy new strings.